I'd say that the architecture that is desirable from the point of view of a large scale SaaS is very different than the one that's desirable from the point of view of a tool that just needs to work for a single organization. And since the SaaS is bringing in all the money, that's where the architecture follows.

> actually a feature

I would guess that for a few people people (e.g. the ones who made the scary visual of rising costs) this is explicitly so, but for most people it's more implied. i.e. I don't think anyone advanced their career with Sentry by making self-hosting easier.