I only signed up to express my dismay about the character of Sheldon Cooper on TBBT, because I can no longer stand the status quo. I don't know why the writers have treated him so badly over the past couple of years, most noticible during the last two seasons. Let me explain:
When you watch "Young Sheldon", you see how the character was supposed to be: socially awkward, yes, but still caring for those he loves and often aware of his own flaws, and - most importantly - capable of learning from his experiences.
On TBBT, on the other hand, his learning curve was always revoked. You see him learn from a mistake he made in one episode, but by next week it is all forgotten, like it never happened. And the worst part: he has gotten even meaner (and enjoying it nonetheless) and more emotionally self-centered and egoistic with every year passing, which made episodes like his wedding a farce to watch, completely unenjoyable because it wasn't the least bit believable for his TBBT character version. And frankly, if I were one of his friends, I would have stopped talking to him a long time ago. There is nothing likeable left about the character, to a point where his "quirks" aren't even funny anymore but merely aggravating.
The character has become so unlikeable that I understand why Parsons doesn't want to portray him anymore (although that might not be the actual reason why he is quitting, but I would have understood if it was ). The writers have done awful, undeserved stuff to other characters too over the years (see poor Rajesh, for instance), but in all honesty, I wouldn't mind a TBBT without Sheldon Cooper in it. I only kept watching for Raj, Howard, Amy, Leonard and Bernadette.
Just needed to get that off my chest...