When someone purchases a home where RV parking is allowed in the front yard, they should fight tooth and nail to save that ability to do so. It can be expensive to store your RV within large cities. With that said, many RVer's are their own worse enemy by having RV's that cover the entire driveway or allow them to fall into disrepair.
I'm not a fan of allowing RV's in a front yard because they can be eyesores, but behind the front edge of the house is fine. In the OP's situation, that might be a reasonable middle ground for new RV owners and grandfathering in of the people who already own RV's.
If you live out in the country and have acres of land, who cares where you store your RV and other types f equipment, but in neighborhoods in large cities it really does hurt property values when someone trashes their house. If you notice, they never really care until it's time to sell their home and then suddenly they want to fix it up, but in the interim, they screwed everyone else whose property value suffered because of their **** hole.
Lastly, we all know what is meant by "trailer park", especially those who have all permanent residents. Obviously, there are nice ones, but that is not what the reference means and it's silly when you argue the point when it's not what the discussion is about.....an issue that is very common here.