Comrade PhysioProf is, I think, looking at Lahde's quotation too narrowly, especially if you look at the quotation in the context of Lahde's full message.
It is certainly the case that there are some people who enjoy being busy, very busy; Lahde's message — and my agreement with it — is not some envious or dismissive attack on such people merely because they are different.
I've invariably found with such busy-by-nature people is that they are the not in the least concerned with their "legacy"; they "work" hard because the work isn't work to them, it's play.
Lahde's screed is not aimed at such inner-directed people. It's aimed at the millions of people who work hard not because they are impelled by their inner nature, but because they are outer-directed, they are responding to familial and societal pressure. More importantly, they have constructed an attachment to destination, not the journey. People are, of course, free to do as they please, but outer-directedness and destination-striving are recipes for unhappiness.
Dick Feynman is, I think, a classic example of the hard-working inner-directed person. Surely You're Joking, Mr. Feynman relates a very important anecdote. Working at CalTech (IIRC) Feynman became very concerned and uptight about his "legacy", about whether he was really doing important work, and he was feeling miserable and unproductive.
He decided, then, that he was not going to worry about whether his work was important or not. Rather, he was going to work on problems and puzzles that interested him, that he found fun. If these puzzles weren't "important", well then, too bad for everyone else. Of course the irony is that this approach led to the work that won him the Nobel prize (which Feynman treated very unseriously).
I see this sort of outer-directedness all over the place. I personally know people making a $1,000,000/year who drag themselves to work with desperate misery. I know wealthy people who have allowed their wealth to change them from kind, caring people into gigantic assholes, paranoid and contemptuous of the rest of humanity concerned only with protecting their wealth and privilege, mistaking their achievement for virtue.
In a related sense, I know people who are living good, happy, satisfying lives, free at least of the suffering of poverty, who are nonetheless miserable because they have not achieved enough, not done work that is really important. They do things, work at certain jobs, undertake certain projects not because they enjoy doing that job, not even because they have to do something to live, but because they think this job and that project will enable them to do "important" things.
But as Lahde notes, there are no truly important things except that which is important to the individual. There is nothing that will grant you a "legacy"; striving for a legacy is doomed to failure. In just fifty years, 99.999999% of people's work will be forgotten; does that make most people's lives meaningless and vain? And even you are one of the very few, if people are still talking about you in a thousand years, you'll be far too dead to enjoy it. What makes something "important is whether its important to you, not whether its important to other people, either our contemporaries or our descendants.
Of course, this is not a call to radical individualism; to divorce one's self entirely from other people. Social interaction, even social responsibility, is important to most everyone's psychological well-being. But it is a curious, ironic, perhaps paradoxical truth that the best, most effective way to be liked is to not care too much about whether people like you, to just "be yourself"; the best way to do "important" work is to not worry whether your work is important. A kind of psychological "sincerity" is more important than ambition.