Although most of Why I Became a Feminist Socialist is incomprehensible mush, Hilary Wainwright does make some important points. It grates, I think, for a self-selected elite to simply impose "socialism" on a recalcitrant, obdurate population. The whole point of socialism is that it should not just be better for the masses of people, but clearly better, and socialism requires the enthusiastic support of the masses of people from the very beginning through to the end. And once in power, simply setting up another oligarchy will not bring about socialism: no oligarchy, however "Marxist" in its internal ideology, will ever voluntarily transfer power to the people.
I really cannot tell what Wainwright is for, but I know she's categorically against the use or capture of state power. "I rejected both the Soviet model and the Harold Wilson, Fabian model. . . . I rejected the so-called Leninist relations of state power and party power, and the Fabian understandings of power whereby the state delivered concessions and policies, rather than power coming from within ourselves." Wainwright seems to reject both a revolutionary capture of the state and a gradual reformist transformation of the state; presumably, she also rejects a perpetuation of the already existing capitalist state. We cannot, of course, build anything even vaguely resembling socialism under the thumb of the capitalist state; the capitalists will simply, and from their point of view justifiably, violently suppress anything that threatens the structure of capitalism.
The only thing left is to abandon the state entirely, and try to then build socialism with nothing that even vaguely resembles a state. But this strategy is profoundly problematic.
First, how do we abandon the state? The capitalists are nothing if not clever. The capitalist state exists not just to enforce the domination of the bourgeoisie and the subjugation of the workers; the state exists to enforce relations of domination and subjugation throughout society. Whites, especially white men, dominate and subjugate black people, men dominate and subjugate women, mental workers dominate and subjugate manual workers, etc. ad nauseam. Even if they want to reform the state, anyone with even a little bit of privilege will always support the idea of the state. The very best that socialists at the individual can do is to contract the legitimacy of the state around only those with a little privilege. But then who fights that state?
There is a problem in Wainwright's article that echoes through the infantile anarchism (including Libertarianism) in general: the distinction between the state as an institution of violence and the state as an institution of domination. But there is no objective distinction between violence and domination: violence is objective, but domination is just violence one does not like, in the service of ends that one does not like, or contrary to one's interests. Thus, racists see state violence used to end racism as domination: surely the state demands that they give up their own interests without satisfactory compensation, ultimately at the barrel of a gun. Domination is entirely relative and subjective; any "objective" construction of domination that does not equate violence and domination must rest entirely on subjective criteria. Thus, The definition of the state as an institution to legitimize domination, is incoherent. Domination is just illegitimate violence, and state violence is legitimate by definition.
Violence by itself precedes the state. Any individual can use violence against another individual. Even technologically (there is no such thing as an impregnable defense), it is logically and physically impossible to eliminate violence. Because the criterion of domination is incoherent, we are left with Weber's definition of the state as a particular kind of institutional relationship to violence: the state is an institution (or coherently connected set of institutions) that monopolize the legitimate use of violence. (Note that Weber's definition does not entail that any violence employed by individuals who comprise the state institution(s) is necessarily legitimate; this definition entails only that all legitimate violence is necessarily employed or sanctioned by the state.) If we get rid of the Weberian state, then we must distribute rather than monopolize the legitimate use of violence. While the monopolization of violence entails some serious problems, its distribution does not seem to solve those problems; only the lunatic Libertarian fringe even tries to theorize about distributing the legitimation of violence. The infantile left-anarchists merely shut their eyes to the problem of violence, pretending, in the most literally infantile sense, that if they cannot see it, it does not exist.
The implementation of socialism will require using violence to dominate and subjugate the bourgeoisie, who themselves cheerfully use violence to dominate and subjugate every other class, especially the proletariat. We can hold hands and sing Kumbaya as much as we want (and, under certain circumstances, that's an effective tactic), but at a certain point we have to say, "Comply or die." This is a harsh truth, but it's a truth that actually exists, however much we close our eyes to it. If you are without money and hungry or homeless, the state forbids you avail yourself of food and shelter; if you do not comply, the state will, in extremis,* kill you. The socialists must say the opposite: the state forbids you to withhold food or shelter from someone in need; if you do not comply, the state will, in extremis, kill you. The capitalist state forbids the workers from seizing the means of production; the socialist state forbids individuals from seizing absolute control of the means of production.
*Of course, we usually don't want to jump right to deadly force; however, "intermediate" force requires the real availability of deadly force if the intermediate force is resisted. A person will allow the police to imprison them only because the police can and in fact will kill them if they resist imprisonment.
The difference between capitalism and socialism is not that one or the other uses or abjures some means. The difference can be only in the ends to which those means are used. All of bourgeois "morality" is simply the social, cultural, and psychological deprecation of certain means when used to overthrow capitalism; those exact same means are "legitimately" used to perpetuate capitalism. And, similarly, socialism must use those same means to overthrow capitalism, because the means of violence are, ultimately, the only means there are.
Even nonviolent dispute resolution requires a foundation of violence. I cannot negotiate with my neighbor unless, at some level, violence of some kind is available to settle the dispute; otherwise, I can just say, "Fuck you. I'll do as I please." Not everyone always says so, but some people do always say so, and everyone sometimes says so. This violence can take the raw form of a police officer with a pistol enforcing the order of a court, or social exclusion from economic life, just as deadly as a pistol. Arguably, the pistol is more honest; as capitalism has shown us, it's too easy psychologically to ignore the violence inherent in economic and social marginalization.
Fundamentally, Wainwright's supposed abjuration of state violence just promoties quietism to preserve her own privilege.