I'm aware of that and Blizzard is wrong - if someone every creates a WoW clone but instead of copying everything Blizz did including its mistakes, only copies the good (smooth engine, art style with longevity) and replaces the bad (hard 2 factions, gear resets, yada yada yada) with better options (soft factions, gear that lasts, yada yada) that's a WoW clone that would do very well.
I was bemused in Rift beta to see Trion had copied the hard faction system: something I don't think anyone not at Blizz ever thought was a good idea.