I like Ali, but this sounds like a half-assed, naive suggestion to me. Of course, I'll look immediately askance at anything that might even indirectly cause more idiots to show up at my door spouting nonsense.
More importantly, while I suppose in some sense Christianity is "better" than Islam (it's hard to get much worse than Islam without shaving your head and wearing a swastika), that's not really the point. The point is not whether we judge (we do that all the time), but on what basis we should judge. And once you've accepted the premise that there's a legitimate basis to judge the difference between competing brands of delusional theological bullshit, you're implicitly denying that we should judge based on rationality and humanism. One might as well debate whether it's better to believe that you're Napoleon rather than Jesus Christ.
The one and only reason that Christianity is "better" than Islam is that in the West Christianity has been for a few centuries under savage and continuous assault from rationalist, secularist, humanist (and to some extent capitalist*) philosophers, intellectuals and politicians. Historically, theologically and ideologically, Christianity without the moderating influence of secularism is just as much a gigantic hellhole of sadistic evil as is modern Islam.
*Capitalism's early struggle in the West was against feudalism, which relied heavily on the divine right of Kings as a propaganda theme; secularism was an effective counter to that theme. Of course, so was a dour, humorless and sometimes sadistic Protestant religious justification. While useful in the struggle against feudalism, rationalism, secularism and humanism leads inevitably to communism, which is why the capitalist ruling class has vastly increased its financial and ideological support for fundamentalist Christianity.
Even her additional goal of wanting people to judge whether one culture is better than another misses the mark. At least culture is real, but the problem is that "culture" is far too broad and complicated to simply compare one against another; there are far too many irrelevant, accidental details about every culture to make such a simplistic comparison interesting. Which is better: Christmas or Eid? Baseball or soccer? Front porches or courtyards? And which is better: Economic imperialism or theocracy? Wars of aggression or terrorism? Bombing abortion clinics or female genital mutilation? Mindless consumerism or mindless religiosity?
The point is that our task is not to judge between delusional systems of theological bullshit or cultures as monolithic entities. Our task is not even to learn that it's somehow "ok" to make judgments. Our task is to learn how to judge rationally, sensibly and humanely. It might have made sense a couple of hundred years ago, but it's pointless today to encourage religious believers or almost equally delusional cultural and national exceptionalists to accept the basic validity of delusional thinking and argue the details of their delusions.