The truth is.. that someone will find an optimal build and 95% of players will use that build. Regardless of their end game aspirations. Also people will get called out and 'bullied' if they don't perform amazing while not using the optimal build. The fights will be arranged around said build and then people will complain that their talent is useless etc. It's a lot more work for the developers for little profit.

I like the idea, love it. But in practise it really doesn't work, almost all MMO's with talent choices have that problem.