I obviously know more about your class than you do, play how I tell you.

[Gnova]

I REALLY hate running into these types of players, typically raiders(not all raiders of course).

Left a expert because I just couldn't handle how obnoxious this guy was. "Have you even cleared coil anything?" Your rotation is wrong, why do Dragoons never listen and always die?"

Died once because a new BLM and WHM didn't know they had to kill stomach on the fungus thing on Lost City dungeon.

Anyone care to tell their experiences with players who think they know better than you?

The way he told you was obnoxious.
But the best way to stop having people tell you how to play your class is to learn to play it well.

Perhaps your rotation did suck and now you will look at it.
If you are playing at 75% efficiency that just means that the rest of the group has to do 125% of the work they should.