what does he know about you?
so far, it sounds like it's all about him.
is he making your life better by being in it?
or has it become your job to rescue him, and at what cost? (you said, "I kept seeing him despte warnings from friends and family. They were in two camps -- He's a loser and you can do better and you are becoming an enabler so you need to stop seeing him.")
one thing I've learned for sure is that when friends and family are all giving me the same warnings, it's in my best interest to take heed.