Yours concerns about big corporations are understandable and I share them (although I won't deny using their services sometimes, I guess I'm a fixer-upper). But sometimes those organizations do good things too and GSoC is an example of that.

My activity past summer in GNU social was sponsored by GSoC, and receiving some income for the time I've dedicated was helpful. I have friends that have to work on the summer in order to help their families. Programs like GSoC allow them to contribute to the FLOSS community while receiving some important money for doing something they enjoy.

GS in GSoC was something I have asked MMN-o for past year but it was ultimately possible thanks to GNU acting as an umbrella organization for its packages. I think GNU understands that GSoC is not something harmful as it brings students to the Open Source world.

I feel that GNU social needs more developers and I believe GSoC can help with that. Finally, even if those developers may help only for the money in the beginning (it wasn't my case but it is legit for the above mentioned reasons), they will eventually fall in love by GS like us and will be helping whenever possible even without the GSoC income. ;)