While Etherpad is somewhat research-y, it is a product. The difference between Etherpad and what SPJ does is about as big as between a mathematician working on car collision simulation and one working on abstract algebra.
Dunno, Paul. While SPJ does have a lot of relevance to current computing, his work is not a product like Etherpad was. I haven't seen YC companies moving towards or staying with fringe languages -- not that I criticize that business decision.
Maybe the YC model will reach that "how will we be computing in 10 years" phase at some point. But (perhaps with good reason?) it does not seem to be there yet.
Etherpad came and went pretty quickly though, at least in its initial incarnation - correct? Simon has been at Microsoft for quite a while. You can certainly do interesting things in a brief period, but some stuff requires just requires more time/capital/materials.
