I doubt we have more of it. But it seems fairly clear that we worry about it more. Two related hypotheses concerning why:

(1) Think about the kinds of things LW commenters do for a living: lots of programmers, a fair number of engineers and the like, plenty of students or people otherwise in academia. Those jobs share the characteristic of requiring a lot of solitary, focused work, which is easy to procrastinate from. Furthermore, in those jobs, we often have the choice of working a little less hard with no obvious, immediate drawback: a perfect breeding grounds for akrasia.

(2) Think about the kinds of things we procrastinate from. There's work, sure, but to a large degree also, there's stuff that we want to be spending our non-work time doing: reading improving books, teaching ourselves more math, etc. Those things (which have a pretty delayed payoff and are difficult and not always fun) share a lot of characteristics with our jobs in being easy to procrastinate from. And the desire to spend non-work time doing stuff like that is clearly massively correlated with LW readership.

If you imagine the ideal non-LW person -- who has a heavily supervised, impossible-to-procrastinate-from job, and who has no ambition to spend evenings and weekends other than in totally hedonistic leisure activities -- that person might be as prone as we are to akrasia, in some biological sense, but essentially never gets a chance to act on it.

Frankly, since I think most of us have more interesting jobs and more interesting hobbies than most people, I think we're correct in general to be worried that akrasia is costing us a lot at the margins.