How is it that everyone is OP?

So just looking down the forums and posts and everyone seems to be OP????
Priest are OP
Mages are OP
Warriors are OP
Shamans are OP
Druids are OP
Loladins are OP
Bad luck, Locks Hunters Rogues
But not DK's since your healing is OP....
Forums just look like a crazy whine for most class's....
This because counters, counter you too hard ? or just that people don't know how to play vs other class's?

do the devs need to lay out some more simple instructions that say when you are class X, you can do this this vs class Y, this this and this vs Class Z etc...

Just seems crazy that everyone thinks everyone else is OP
Although i have to laugh at the Remove mounts post ;)