Unpopular opinion- alan gets unnecessary hate
Even though alan was a leech and a cheap insufferable prick, there is a reason why he was this way, he had a horrible childhood, being constantly bullied by the one person he looked up to, charlie. In one episode he even said, 'i started looking forward to the wedgies as that was the only love i got'
He was also sidelined and hated by his mother, then had his life go to shit when charlie slept with his lawyer. He really did not deserve any of this.
So even if he becomes completely insufferable as the show goes on, we cannot call him out to be any worse than others in the show as they are all equally if not more horrible.