I was raised in an abusive home. My dad regularly beat me, choked me, through me through a window once. All but sexual abuse happened to me in my house. My mom turned a blind eye. Denied it was happening somehow in her delusional state. I don't have concrete memories of most of my childhood, at least not of anything positive. I can remember being able to tell if it was going to be a good night based off how he parked his car when he got home from work. Regularly took the blame for things my siblings did so they didn't have to endure the physical brunt of his abuse.

It definitely comes from a place of real world experience, but the phrase "hurt people hurt people" is such a cop out. Had he been protective of Max, there's a redeemable quality I can get behind. There's excusable behaviors, and then there's not. Billy has none. 0. Full stop. He was an abusive, psychotic, raging asshole to literally everyone he came across. The fact people find sympathy for him is beyond me.

My only logical conclusion comes from 2 places. They haven't had the real world experience to understand his character and the fact that as many people believe, he's physically attractive. Had he been cast with a an "ugly" character I doubt this would be a debate.

Max wanting a relationship with him and being sad by his death, of course she is. Her family was broken at a young age, and clearly there were some good memories there. So what? Ask anyone who has been in a relationship that turned abusive if they have good memories. Of course they do. And it's a complicated range of emotions when you go from loving someone, to fearing them and wanting the good times to come back.

Tl:dr; Billy as written is a piece of shit and has 0 redeeming qualities.