The main reason for this is described in your post above, taken to its logical extreme you end up doing seemingly crazy stuff like trying to stop people from creating baby universes rather than solving friendly AI.

There are many arguments in this thread that this extreme isn't even correct given the questionable premises, have you read them? Regardless, though, it really is important to be psychologically realistic, even if you feel you "should" be out there debating with AI researchers or something. Leading a psychologically healthy life makes it a lot less likely you'll have completely burnt yourself out 10 years down the line when things might be more important, and it also sends a good signal to other people that you can work towards bettering the world without being some seemingly religiously devout super nerd. One XiXiDu is good, two XiXiDus is a lot better, especially if they can cooperate, and especially if those two XiXiDus can convince more XiXiDus to be a little more reflective and a little less wasteful. Even if the singularity stuff ends up being total bullshit or if something with more "should"-ness shows up, folk like you can always pivot and make the world a better place using some other strategy. That's the benefit of keeping a healthy mind.