1) I wasn't making a judgement in this particular post, so your "Why not?" seems to me to be an attempt at some sort of childish sophism.
2) So adding most popular subclasses doesn't necessarily lead to increased build variety.
It may seems like anything you want my dear, but i noticed you didnt answered either question ...
Should i presume you dont have any valid answer?

Well, who am i fooling ... obviously i do presume that, and i obviously i presumed that even earlier ...
Its all about mindset.

If you want to ignore everything you have unless its the "most effective" option, its up to you ... i certainly plan to play this game several times and i will most certainly appreciate that i can set my group of heroes differently at least a little for each play. :P