Felt bad for De Niro's character

His didn't deserve what what he got, and so what if he busted Joker's balls a bit. The guy was a terrible comedian and his career was going nowhere. At least De Niro gave him some exposure then even invited him on his show. He was nice towards him in the backroom and even let him go through with the whole clown charade. I highly doubt Joker's career would've exploded after that, but he would have got his 15 minutes of fame and possibly have made some real money. On the other hand Thomas Wayne was an asshole of epic proportion, and I didn't feel bad watching him get shot. In fact if the Joker did it personally all the more better. All the talk show host did was tease him, but more importantly he gave him an opportunity. What gratitude does he get for it? None! Just a bullet in the head from a psychopath