Andy really is just a twisted reflection of his parents, especially Tom.
Both Tom and Andy have 3 things in common:
1. They're both lazy fucks
2. Both expect others to do everything for them
3. Both blame others for their own problems.
Every time Tom got inconvenienced by Law enforcement, he says something like "You all hate me cause you corrupt", "They're are all idiots" or "Not the fucking government again"
Replace "Corrupt" with "Buze" and you got yourself Andy.
As for Janet, the only thing i can think of as to why she deserves Andy is that she most likely coached Andy into lying about the sexual abuse allegations against Mike and actively contributed to Tom getting rid of both Mike and Danielle, as Andy himself once implied in a conversation with Tom.
The more you know about the couple, the less you'll feel sorry for them. Just watch the video of Andy complaining to Tom that royal care won't let him bring children over to his room, and Tom just calls the caretakers idiots and claims they're conspiring against Andy. Bob Chandler types of enabling right here.