Well it's the generalisation about a large community that is the problem, whether put arrogantly or not (the arrogance only makes it harder to scroll past and ignore). GP put it well:

> I'm always confused when someone calls out a large group of people for not having a consistent opinion.

The way I read OP was "given that X flip-flops, it's weird some people talk as if X is constant" (i.e. acknowledging the inconsistence in opinions and, further, calling out those that don't)