Microsoft shouldn't push out an RTM product and call the broken bits "Preview" to absolve themselves of the responsibility to deliver a reliable product.
I was evangelical about .NET Core. I stuck with it for years. I stuck with it when Damian admitted that he "doesn't build web apps". I stuck with it during the Release Candidates. It's only when they pushed this out the door and called it RTM that the penny dropped and I accepted the project had been mismanaged.
Why complain if you understood the status and assumed the risk?
If you knew anything of the traditional release history for Microsoft you wouldn't have commented. All your post demonstrates is total ignorance of the context or history.
It was previously totally fine to use RCs for the last decade, probably way before that too, but I only have experience from then. RC in MS speak meant "pretty much finished, API won't change unless we find something desperately wrong".
Then it suddenly means basically pre-alpha, "anything can change, massively, between RC versions".