I wasn't really talking about difficulty (or lack of), I was simply talking about everything being predefined - the big puzzle here is just to figure out what style to use on what enemies, and it's nailed. The next time you go through the game, no matter how you place your talents, you'll still end up using the exact same styles on the exact same monsters. That becomes tedious.
Leaves the player with very little choice. You can't become an incredibly strong, slow/hard hitting warrior relying heavily on strength, or an agile swordmaster using speed to dispose of his foes. You use strength against heavy opponents, and speed against dodging ones. Geralt is always everything at once, and you always have to use the fighting style that is designed to kill monster X, not whatever style you actually prefer.
At least, that's my perspective. If you're really stubborn, I supposse you can use fast fighting on everything, but you'd have a really hard time against some of the heavier opponents. Likewise, if you rely mainly on strength, it's virtually impossible to beat the dodging ones (can't hit them).