One of the founding points in WoW's talent system, or any game's talent system, is to allow players to customize their characters based on their personal preferences. Want to play a healer with your Priest? Great, here's a few dozen holy talents. Your Paladin needs to crit some face off? Retribution is your key.
Within each of these talent trees are many, many choices. And while cookie cutter specs eventually develop, the option is still there to allow for whatever spec or combinations of specs you decide works best for you. The rest of the world be damned, it's your choice.
However there are some exceptions to this. These occur in talents that we all need to play, more or less. Or in more specific terms there are talents that the rest of the tree is designed around. One such talent is Titan's Grip, and according to Ghostcrawler Blizzard is okay with that (for now).