(And some Protestant denoms don't necessarily think that other Protestant denoms "got it wrong," only that they "got it differently.")
I believe it was St Augustine who said, "Unity in essentials, diversity in non-essentials, charity in all things."
Certainly MANY Protestants would say the same thing about other Protestant denominations.
Obligatory Mormon reference: Brigham Young said that the penalty for interracial marriage was "Death on the spot" *and* said that this doctrine could never change. Today interracial Mormon couples can have their marriages "sealed" in the Temple.
(Which, of course, makes Brigham Young a false prophet...but we only hear crickets from the Mormon faithful about the obvious conclusion here)
Heck!
I'd say it about CATHOLICS, too!