http://jacksonupperco.com/2017/01/10/the-ten-best-married-with-children-episodes-of-season-seven/

In the show's True Hollywood Story, the original creators said they were always getting pressure to make it more of a traditional family sitcom, to be more cutesy and show they really love each other under it all. The show was obviously conceived to be the exact opposite of that, the mirror image of The Cosby Show specifically. Eventually the original creators got fed up and left. That must've been when they got the bright idea of introducing Seven. And the tone did change where there were many more shows with the family bickering, and then showing the did love each other underneath it all. A few of those episodes would be fine, but they did go against the original concept, and in the later seasons there was an overkill of them.

This is one of the worst seasons. I like most couldn't stand Seven. I never understood why they thought it was necessary to add a character like that.

Yeah, this was the one show that DIDN'T need a Seven-like addition.
To date, no one has owned up and claimed he was their idea.