That's true - although that should be an incentive to write and release good Open Source code! Even if a single person gives you $0.25/week (the minimum amount) you'll get $13/year. We're attempting to give most developers at least $1/week - and I should emphasize that this is only from Khan Academy. Just because we're giving this amount it doesn't mean that these devs won't get money from other sources. I, personally, receive donations from a couple dozen users on Gittip with a wide variety of amounts (most being in the $0.25 range).

It's very defeatist to give up before even trying ("only" a cup of coffee). Why not aspire to more?