"MOAR DPS" <> "play better" - unless you are a damage dealer.
Read what I wrote instead of picking a single point and trying to score points. For me, the reason I chose to be PLD was not so that I could try to min max my DPS, it was so I could be a defensive wall protecting the party.
Many (if not most) healers play healer not to min/max for DPS, but to heal and keep the party alive.
Those are the roles for a tank and a healer. Damage dealers started playing DD because they like to see big numbers and things dying quickly, they do (or should) focus on min/maxing for optimum DPS.
I'm not suggesting that healers and tanks have nothing to contribute, but let's be honest, it's not their role. In a farm group, as I said, I agree that if you join a farm group, then DPS is expected to be high since that's the point of farming content. Obviously high DPS, = skipped phase(s) = quicker kills = more runs per hour = more drops.
But, that doesn't mean that the "MOAR DPS" meta needs to be shoved down players throats outside of the end-game (including farming groups) environment.
But to address the implication of your post, MOAR DPS isn't "play better" since it can often lead to standing in stupid. "Play worse" has nothing to do with anything I said, nor did what I said translate to or endorse 'playing worse'.
Now, before anyone posts the math that says that by focusing on DPS things die quicker which translates to less incoming damage during the fight, etc.... yeah, I know. So let's all roll damage dealers instead shall we? Oh wait, I don't want to play a damage dealer, I want to tank, or heal.
Your post is a great example of how prevalent "MOAR DPS" has become and how damaging it is. The logical extension of your point is simple, if you focus on your role instead of DPS, you're playing worse - making DPS the only measure of skill or worth in the game. That's pretty crap actually, If I wanted to play a completely mindless button masher focusing on damage rather than my role, I wouldn't be playing this.