I don't know...he just tries so hard and fails...tries again, and again, and again, etc.
Backstorys...Trusting P the P with everything his accent blah blah blah
He's the Funniest, Dumbest Evil Dr i know!
He's always messing up his plans and that makes Candace not get believed about Phineas and Ferb.
What's not to like about him?
HES JUST THE FUNNIEST GUY! and its not like he tries to crack jokes up, its just his whole life sucks sometimes is so funny! like when he said "It's not the worse date I ever had. There was the one that kept stabbing me with the fork. " or when he starts to realize things he should have realized 10 mins before, or things that dont matter at the moment, hes just so calm about everything, and hes ugly, and he tries to make people uglier than himself so he looks cute,with his 'inators' when he can just do the opposite! its hilirious, keep it up doofenshmirtz!
Ever seen the one where he has to be a gnome. "Sucedan deeneesh!" Or something like that. He always reveals his plans and his backstories are hilarious.
The satire of what he does, and sometimes the irony and stupidity.
he fails in a funny way
(in other words everything)