A good point, though I think most people take the stitch it together approach because they either have existing processes or proven tech (so startups make sense) - however generally picking an all in one often means that the base cases (like getting started) are awesome, but the edge cases are a razors edge (no familiarity with your product).

As a former DBA I got to see the general purpose databases bolt on a lot of shitty addons, and a lot of upstarts build just enough to get the sale done (or targeting bigger customers than I) - I hope y'all can get enough polish and reliability done and grow into something I want to use in five years :)