Kenan and Kel Explained

If you're a 90's kid, you've probably watched the hit show Kenan and Kel. Kel stays with Kenan all the time, and we never see Kel's house or parents. Why?

Kel gets abused at home. His mom smoked meth while pregnant with Kel, so he got brain damaged.
Kel drinks orange soda because it's like alcohol to him. The more orange soda he drinks, the more happy he gets.

Chris Potter, owner of Rigby's, always talks about "Mother". We never see Mother though. Why? Mother is super unhealthy. She is in a wheelchair, and she has a disability. She isn't shown because she would upset the children watching.