Every time I pay for electricity for my computer rather than sending the money to a third world peasant is, according to EA, a failure to maximize utility.

I'm sad that people still think EAers endorse such a naive and short-time-horizon type of optimizing utility. It would obviously not optimize any reasonable utility function over a reasonable timeframe for you to stop paying for electricity for your computer.

More generally, I think most EAers have a much more sophisticated understanding of their values, and the psychology of optimizing them, than you give them credit for. As far as I know, nobody who identifies with EA routinely makes individual decisions between personal purchases and donating. Instead, most people allocate a "charity budget" periodically and make sure they feel ok about both the charity budget and the amount they spend on themselves. Very few people, if any, cut personal spending to the point where they have to worry about, e.g., electricity bills.