Stonebraker has done a lot of fine work, but also has a lot of false negatives; he got down on recursive queries, on data-parallel compute, and generally most other things that he's not directly working on. It ends up with an in-crowd of folks who think he is great, and an out-crowd of folks frustrated by his constant unfounded dumping.

I've personally found it is hard to take him seriously when he says a thing, and you should first check which company he is currently flogging. Doesn't mean he is wrong, .. but check.