I never said you should refrain from telling someone when you believe their viewpoint to be wrong, but that’s not the same things as demeaning them for disagreeing with you.
Good Christians do NOT demean people for disagreeing with them (or at least they shouldn’t do). Unfortunately people often take criticism, particularly negative criticism, to be demeaning. But that’s not the fault of the critic. Homosexuals believe they are being “demeaned” by Christian organisations that refuse to sanction their practices by “marrying” them. They think they are being forced to be “second class citizens”. I think they are doing that to themselves.