This doesn't just punish sorcerer and isn't a "single ruleset for Sorcerer, and second ruleset for everyone else." It's "a single rule for Quicken Spell, and universal spell rules for every caster including sorcerer."
I dont see difference between those.
My Sorcerer can cast only one damaging leveled spell ... but your Cleric can easily cast two leveled heals.

And you say that is balanced?
No. Your Sorcerer can cast two spells just as easily as my Cleric. The spells just naturally have to be a bonus action.
Your sorcerer can cast Misty Step (or Dragon's Breath or Magic Weapon) and Fireball; my Cleric can cast Spiritual Weapon (or Healing Word or Sanctuary) and Cure Wounds. But your cleric can't cast Heal and Cure Wounds because those are both actions, just like my sorcerer can't cast Fireball and Burning Hands.
Yes, just like Wizard can, just like Warlock can ...
I dunno, it just dont feels right i cant help it. :-/
I see what you mean, i understand it ... but i just see that diferently.
