If you look at xbox's videos he/she kites alot of stuff. Alot more things than I ever do. Also the gear level was significantly lower than what most people were achieving.

Even if 1tank 4 dps are clearing heroics before 5dps groups doesn't mean that 5 dps won't ever be able to do it. Given enough time to try out strats and figure stuff out they will eventually figure it out.