Could drinking and being abusive to girlfriend have come from a failed career? You don't think that's enough to drive someone to drinking? I'm not trying to justify any of it but only pointing out that these aren't isolated situations.
If the guy is a woman-beating alcoholic then he's a woman-beating alcoholic, no matter how he got there.
This guy still got a number of multi-million dollar contracts despite barely being able to play, and that's more financial success then most people achieve in their lifetimes. That's enough money to start a business...and even if he can't play basketball it's not like the guy can't get an education and a regular job.
Blaming his lack of career success for his actions would be perfectly typical of today's world, where everybody tries to detach themselves from responsibility of their actions by using sob stories to try to gain sympathy (and an excuse) for being a horrible person. Not to mention today's ever growing trend for people to look for somebody to point fingers at every time they make a mistake.