They were both dysfunctional, warped people.
But both used to have far more full, capable lives.
Don't you think 1980 Borb were vastly different than 2010 Borb?
In 1980, they were both barflies who had fun. By 2010 one was a hoarding snorlax, and the other was slowly dying from bed bugs.
I really think that both Chandler parents need to be considered separately, not together.
Barb, even before meeting Bob, seems to have had a consistent pattern of not being able to form lasting bonds with people, even her own family. She apparently had a long working career, yet never maintained any contact with her former co-workers. There was never a mention of spending any social time with neighbors, and what socializing she did do what apparently in bars. Cole indicates she had a few flings with numerous guys, none of whom stuck around very long. Granted, this last information is gained through the Cole Filter, but there's no reason to consider it inaccurate in light of everything else we know. Even her family seems to have deliberately cut ties with her, though whether this was all at once or gradually is unknown. So Barb could not form bonds with anyone, and the bonds she did form were ultimately self-serving. Now is it surprising that her strongest bond is with her Tard son, who is basically her housepet?
Bob, on the other hand, did get married and had a family, though unfortunately the marriage didn't work out. He was an outgoing sort and enjoyed talking to people from other cultures. Like Barb, he was not on good terms with his offspring, but apparently there was some effort made to repair that, albeit unsuccessful. Bob was even a part-time radio DJ, which is a gig you don't get without at least a modicum of people skills.
Born were obviously both dysfunctional parents that created a dysfunctional family. No argument there. However, I'd suggest that Bob, left to his own devices, might have ended up having a fairly normal life, albeit with many regrets. Barb, on the other hand, never had a chance. Even if she hadn't met Bob, I'm willing to bet she'd continue to prey on the emotionally weak for as long as anyone would have her. Ultimately, she would still become a shut-in once the bar scene no longer worked in her favor, and would still eventually turn to daytime TV and hoard building to fill the void that was once filled by male attention.