Yeah, it does seem fairly healthy, but one has to admit that Boston would be a very different place today if Microsoft and Facebook (and YC) had stayed. At this point Kendall Square really is all about the biotech (aside from the research offices of big west coast firms like MS, Amazon, and Google.
Also troubling about Boston startups is the frequency with which the best get bought by SV companies. Seems to me that this also tends to limit local growth. So not bad at all, but not what might have been either.
You basically just said what I'm saying, but in a different way. If you're not biotech, you're not particularly interesting to the Boston VC community. Not to say that you can't start a company without VC. But if you need VC, the Boston non-biotech venture-backed startup ecosystem is dying a slow death.
Also troubling about Boston startups is the frequency with which the best get bought by SV companies. Seems to me that this also tends to limit local growth. So not bad at all, but not what might have been either.