So, that was a long winded way of saying, "okay, if this community taboos buying fuzzies rather than optimal philantropy [note: there's a lot to unpack in that], then what's to stop this community from sliding down the undesirable slope towards ultimately tabooing any nonessential personal spending?"
The answer is simple. While completely avoiding nonessential personal spending is suboptimal in the most obvious sense it's, as you alluded to, unmaintainable. I.e., a society like that is likely to die from emigration and stagnation.
Here's an example of tabooing and how it works in realistic terms: Large SUVs, especially in certain areas, have become taboo for their environmental impact. Now, you could say, "if we're going to taboo large SUVs for their negative environmental impact, why then don't we all ride bicycles, because that's obviously where this is leading, isn't it?" But, no; that isn't where it leads at all. The taboo is an communal awareness of an obviously bad thing.
On lesswrong, and in this context, we could start with tabooing pet charities, and quickly move towards your example, but I'm doubtful that we would find that we'd want to take that to dystopic levels. And this reminds me of a common criticism of consequentialism in yvain's faq:
7.1: Wouldn't consequentialism lead to [obviously horrible outcome]?
Probably not. After all, consequentialism says to make the world a better place. So if an outcome is obviously horrible, consequentialists wouldn't want it, would they?
(also, personal objections are irrelevant in the context of a community taboo; "but I drive a hummer because I want a warmer climate!")
"okay, if this community taboos buying fuzzies rather than optimal philantropy [note: there's a lot to unpack in that], then what's to stop this community from sliding down the undesirable slope towards ultimately tabooing any nonessential personal spending?"
Just for reference it should be pointed out that people have already attacked people spending money on medicine or buying cryonics based on this reasoning on LW.
Saw this on reddit.
http://www.reddit.com/r/atheism/comments/ydsy5/reddit_help_me_find_some_peace_in_dying_young_im/
I couldn't help be moved by this. I felt a very strong sense that she is one of us, whoever "us" is. Looking at some of the negative comments and worst of all bad arguments people are using as reasons not to donate made me more upset.
I hope some here might join me in dismantling them. I'd also encourage those like me for who this buys a lot of warm fuzzies to donate. Though it might be wise to wait until we hear from CI or some other third party on the matter.
Edit: She has since made a comment on LW! The provided information has made me pretty much certain that this is a genuine plight.
redditors where willing to give her money to go skydiving, they don't want to give her money to buy cryonics. Sometimes I can only weep.
I think it pretty clear that promoting efficient charity in that particular thread is very unlikely to result in people giving money to better causes. Also I just plain want her to be rewarded in some small way! Note the part starting in the second paragraph that I bolded, not only did she realized what she really was, but she stepped over the entire set of pro-death rationalizations and faced the social pressure people she loved exerted on her because they think she might go to heaven ... its not her fault that a few cells in her brain went haywire before she could afford an insurance policy, I just don't want people like that not having something to show after getting so much stuff right.
2n Edit:
For anyone who just realized the universe sucks and wishes to do something about that whole people dying thing, they are welcome to engage in some optimal death defeating philanthropy by donating to The Brain Preservation Prize that has been endorsed by both Robin Hanson and Eliezer Yudkowsky.