Out of topic, I think the way DRF project funded is very interesting, i.e. public funded fulltime developer working on OSS. How many other similar successful OSS with such funding?
* Ruby Together - https://rubytogether.org/
* Django Fellowship Program - https://www.djangoproject.com/fundraising/
* Read the Docs sponsorships - http://read-the-docs.readthedocs.io/en/latest/sponsors.html
I think the business case is clear enough to make for a big project like REST framework. It's a relatively small investment per-company, but the relative payoff if we can hit a level that keeps it sustainable is huge.