I don’t even think the balance even come close to “you can pick whatever, no need to be the best one”.
Take Paladin for example, Ashen Hallow is a 4 minutes cooldown 1.5 sec cast time Consecration, which will undoubtedly be literal garbage for PVP and probably good in a PVE fight where you can stand still.
This talent will put every Paladin players at a crossroad wether they want to PVP or PVE, if Ashen Hallow was a talent, it wouldn’t even be considered suboptimal talent, it would be considered a trap talent.