Yeah, it was a real thing around the same time people thought high kicks didn't work in MMA. Bas Rutten was the biggest fighter that comes to mind. GSP working with Roach was a big eye opener for a lot of people.
The most interesting change in perception to me was that fighters thought that the most successful boxing style in MMA would be a hunched over Frazier/Tyson style fighter because they'd be in position to sprawl easily, but then people like Frankie Edgar started rising to the top with more traditional upright boxing stances and footwork, evading grapplers.
The game has changed and changed again.