2) The abundance of hard CC encourages the philosophy of using stuns as openers: Most classes do not need CC as an offensive tool, but almost all can and do use them this way.
I disagree. Maybe they get away with it sometimes, but opening with a stun is an easy way to spot if someone is an inexperienced player. Good players save theirs for when it's needed for an objective, or for when their target is at low health so that they can't escape. Opening with a stun, unless you're a stealth class, is pretty wasteful, especially since most classes need a setup before being able to burst.