They saw an opportunity and they took it.

Companies don't have morals. Too many people in the room, generally, for such a concept to make sense.

They have goals, means, and constraints.

Possibly. It's also entirely possible that it results in very little change; I don't know that most users downstream care enough about life at the sausage factory to be deeply concerned of a changing of the guard in their package repo.

I could be wrong; Ruby tends to have a particularly passionate and active ecosystem of developers.

This will result in continued attrition for Ruby, Rails, and the overall ecosystem, just like everything DHH has done over the last five years.