On the one hand, if you grew up in the baazzar, moving to the cathedral might feel like the "death of open source" even if it is really just a return to an earlier way of working. On the other hand, while not accepting external code contributions will certainly improve their security posture it will also make it more difficult to identify who to invite to join the priesthood.
I’m never getting accustomed to the fact that there’s now an entire generation of coders who have never seen a world where "everything" is open-source and developed in the bazaar style (are people these days even aware of the metaphor or Raymond’s book?), a world in which the frigging Microsoft is a major OSS vendor and in charge of facilitating most of the open-source programming on the planet. Try explaining that t…
(Sorry, accidentally negated my meaning there, what I meant is that they have only seen this current world. Or never seen a world where it isn't the case, to use a confusing double negation.)