It does seem strange to me that so few people are paid to work full time on ruby etc (core tech) when you consider the massive total benefit from making ruby a few % faster or better. Why is the funding not there?
There are a bunch of core contributors that are very active. Several of their companies allow them to spend time contributing (most of them are from Japan). Another example is Aaron, he is on Ruby core and his company allows him some time to contribute to open source, so this is sponsorship in a way. I while a company stands to benefit from sponsoring a full time developer, they benefit just as much if someone else sponsors a full time developer. Right now there's not enough companies with either a business incentive, altruism, or interest. Perhaps there are companies out there interested in sponsoring full time devs who just don't know how (and to your point cannot find them) but I think that would be the minority case.
> Oracle Labs pays two people full time (including me) [to work on JRuby] and a PhD student, and more soon.