It seems a shame that to grow, companies are backing away from the vector that got them there: open source.

I agree that current cloud providers are gaining more benefit from open source than they're putting in. So, it seems logical that the main developers want to recapture some of that.

On the other hand, open source is supposed to help build a bigger pie. If the pie gets bigger faster (i.e. more people using CockroachDB) then is the recapture worth it?

It seems the smaller companies think so. But, I don't know of a solid analysis that shows this to be true.