Most people aren't watching what you're doing in casual content. People start to scrutinize your play when things go wrong. You might get suggestions about strength gear if you're losing aggro consistently, but I'd be very surprised if someone from DF insisted that you stance dance to do more dps.

This "meta" isn't really a new or even a controversial issue in raiding. The reason it's being made into a big deal now is because you're seeing people clear content with non-PLD MTs, and the assumption is that it's entirely a dps vs. mitigation issue, rather than personal preference on the part of the tank.