I'm sorry but this is a discussion about their competence. You can't separate someone's opinions on technical topics from their competence in the very technical field you're discussing. If a cartographer has the "opinion" that the world is flat then that directly speaks to their competence as a cartographer.
For starters, "the world is flat" is falsifiable and trivially disproven with evidence. "Dynamic types are better" is neither of these. If you're going to pin someone's professional value to a single technical opinion, you should at least be able to back it up with data.
