I used to take care of a non-verbal autistic man in his 20`s. This was a very good gig for me at the time, as the pay was good and the work was set to be pretty easy. The situation, I am reminded now, was eerily similar to the Chandlers' current situation.
During my orientation meeting, I was surprised at how much time was dedicated on how the mother would be a challenge to my role as caretaker. Even though I was part of a group which included medical doctors, therapists, a bevvy of social workers and psychiatrists; the mother's wishes could overturn virtually any suggestions made by any member of the staff. And she made use of that power all the fucking time.
My first day at the house, it all became obvious that I was walking into a fucked up type situation. First of all, there was a note from the city on the front door outlining the consequences which would befall the homeowners if their trash was not picked up (there was a row of trashcans on the curb, but I had not noticed at the time that it was not garbage day.) Inside, there was shit everywhere. Boxes chock-full of dollar-store-tier toys, pool toys, plastic piping, shit DVD series from tv promotions: 'Golden Girls: TV appearances,' 'The year 2000 in Hockey' etc. The sort of thing I had only ever seen on TV. There was supposed to be a box with my picture in it, to show Autistic Man and remind him that I was new and coming to see him (if he had the picture in his hand and saw me, it was supposed to ease his mind or something.) I would quickly learn that Mother was a shut-in, and purchased everything online. That, or she made us caretakers leave her autistic son alone and buy fucking groceries. Of course, her son was a nervous wreck. Our job was to rehabilitate this poor kid for the eventuality of his mother's death. Even non-verbal autistic people can contribute to society if properly supported and supervised.
Not in that house though.
Mother would have none of it. She was very weary about letting her son out of the house, and she much preferred that we stay close by. One of our projects had been to try to get Acoustic Man ready to move out. Mother had pleaded and bargained until the compromise which was reached was to have him move in the basement of the same house. Oh yeah, and the house was so fucking disgusting, that one day when I went to find clean clothing for Autistic Man, there were maggots in his closet. Probably a result from her bringing food to his bedroom whenever he wanted it, and leaving the dirty plates there for weeks at a time (pretty much until one of us took care of it.)
It's simple, really. She had become dependent on her son, as much as he was dependent on her. Her life revolved around ordering pizza, watching Nancy Grace and old Battlestar Gallactica episodes. The last time I saw her she was saving enough money to go on a cruise to see Dirk Benedict. Predictably, she did not end up going. She found all of her life's meaning in her relationship to her son; which was toxic. She gave him everything he wanted, when he wanted (which, you know, makes the breaking-the-autist-out-of-his-shell job impossible) and he gave her satisfaction that she wasn't just a leeching fat-ass, watching TV and eating junk food all day. Even though, to be fair, the caretakers were doing most of the work.
Maybe it's because I have this experience that I never did wonder about the relationship between Chris and Barb. What else does she have going for her? How would she possibly feel like an accomplished individual if it wasn't for her son? Chris needs her, and that gives her reason to be. Ain't no homo troll gon' get in the way of that love. When she dies, Chris will be as lost as Autistic Man, I imagine. Severed from Barb, he'll probably bounce around from caretaker to caretaker until they get sick of his shit. He'll either commit a crime and be jailed, or he'll have to be put in a ward where a well-meaning, but weary psychiatrist at the end of his rope will prescribe him some drug to null most of Chris out. I think that's what they did to Autistic Man. Last time I checked in with the staff, my coworker was playing 3DS in their living room while Autistic Man drooled and made animal noises.
I quit the job a few months in, because it was too ridiculous. I don't even feel bad for stealing the original Twilight Zone series on DVD. There's no way anyone would notice.
*tl;dr Chris and Barb are co-dependent. When one goes, the other will not survive long.