You don't need many IQ points to wave and say "welcome to Walmart"
Hell I have seen mungs at Walmart WITH HANDLERS do that job but Chris can't?
I've always said (before Chris' current bout of insanity) that I believe Chris could possibly get and hold a job with sufficient pressure from someone like Barb. (Pretty much just Barb.)
Barb's too feeble now, but in the past he had a real fear of her and would do whatever he said. And like you say, some jobs exist that Chris could perform. Chris is also more functional IRL than people give him credit for. He's annoying and dumb, but he can talk to people and get his ideas across and things like that.
But he does tard out sometimes and that's not good for continued employment.
But even when Chris was less crazy, I still thought he'd have to take a couple of tries before learning how not to get fired. I think Chris would've gotten a job at mcdonalds, gotten pouty about having to job something the boss said, and get fired. And then Barb would scream at him and he'd reluctantly keep his mouth shut at the next job.
I think he'd eventually manage to make it work, if only out of fear of punishment from Barb. (Or if she was dead and he was desperate for money.)
The thing is, that scenario is not what anyone would call "stable employment". That it's technically possible for Chris to sort glass doesn't mean they don't consider him teetering on the edge of poverty because he's too retarded not to whine when the boss tells him to do something, "but I'm tired~~~".
There's no hard answer to whether or not Chris could be employed. It's a definite "maybe". Both sides make good points.
But I don't think it's unreasonable for people to side on the side of caution and just say "just because he can technically stamp license plates in prison, doesn't mean we consider that reliable enough to gamble his well being on".
And all this was back before Idea Guy.