I'm the one who once liked Tommy in the early game. For his good sides. Because Tommy is a good party animal and in these moments he really reveals himself as a symbol of the DIKs fraternity: cool guys who love to have a good time. He has balls unlike most DIKs and is not afraid of alphas. Tommy actually apologizes to Tremolo for being a bad father and takes him to a bar. He copes with the internal crisis after the mansion ruining and joins the common cause, finding a job, leaving the infantile bubble.
But the further into the game, the more his bad sides are visible and they outweigh the good:
1. Tommy is a drug addict. And not just to smoke weed, he injects all sorts of rubbish into his veins and can't come off. Heroin, hello. He steals money from Heather for the next dose. He makes a deal with Vinny because of this, which leads to problems later.
2. He breaks the agreement with his girlfriend that they should talk to each other about "pluses" and do it again and again, thereby cheating on her.
3. Tommy breaks the DIK secret code twice: with Derek and then with Tremolo.
4. He lies about Vinny's "prop gun", which puts Tremolo in real danger to his life. Even Quinn did the better job there, warning MC to not mess with Vinny.
5. How insecure do you have to be to be afraid that someone will have sex with your sister? If Tommy thinks that makes him a cuck in the eyes of others, then this guy has serious self-esteem problems. If Tommy would have F95 account , he would be one of this fanatical anti-NTR crusaders

Tommy doesn't care about Josy, but only about his reputation, I think.
6. It seems like he is jealous of Tremolo and his success. He is constantly skeptical of our guy and he clearly doesn’t like it when he succeeds: “Fuck you for being that good.”
So it feels like Tommy is evolving from a controversial character to a negative one. I even suspect him as a potential traitor, because when a drug addict goes through withdrawal, he will do anything for a new dose. Maybe he snitches on DIKs for money?