Well DPS is equally essential for the success of a group. It just so happens there are far more classes that are pure dps than there are tanks so we’re over supply…
My chosen class is a rogue. I always wished they designed combat spec to be a dodgy/evasion tank spec like the Demon hunter on live. That way when I need a group I could just simply click my tank spec. Probably why I actually main a DH on live. But sadly, blizzard gave hunters, locks, rogues and mages only one role so I have no choice but to roll a diff class. I’d rather not do that since I find rogues the most fun to play, especially in pvp