Uh, I wouldn't call it predatory. It's a shame they don't contribute more and they could do a lot better, but turning projects into services massively contributes to their ecosystem.

Maybe predatory is a strong word. Many OSS projects would characterize them that way though, I think. Your point about impact to the ecosystem is a fair one, but in some cases it is more co-opt rather than contribute.

I think a lot of that is perception. I know the AWS RDS team has a pretty close knit relationship with the Postgres team, it's just not super obvious.