I'll say this about the Chandlers. Both Bob and Barb were/are assholes. Both Bob and Barb were estranged from or disowned by their entire families. (pretty much) If all of your relatives want nothing whatsoever to do with you, that says something about the kind of person you are. Bob and Barb were two drunks who ended up getting pregnant, probably accidently, although Barb might have gotten pregnant to prevent Bob from leaving her.
The reason that Bob and Barb stayed together even though they didn't like each other was that all they had were each other. Both had previously failed relationships/marriages, families that wanted nothing to do with them, etc. Together, Bob and Barb could pool their meager resources and survive throughout their retired years. Chris was just an additional factor keeping Bob and Barb together.
Bob and Barb also shared the same persecution complex, unwillingness to take or teach responsibility, many of the same delusions, and an attitude of "take whatever you can, give nothing back" to the world. Chris was born with Autism, but he was raised in a sort of isolation by two selfish, thoughtless neurotic assholes who stayed together for convenience. It was a weird dynamic that kept the Chandler household together, but it worked, and it helped produce the manchild that we all know today.
