I have lived in Allen since '90. Quite honestly, I don't want to see someone else's project, RV, etc sitting out front on my street or in my neighborhood. Fortunately, we have rear-entry garages where I live, so people can hide their stuff.
I agree...if its covered and parked on an improved surface, they shouldn't mess with it.
BUT... for every one who tries to keep their project out of side and clean, there are 50 bozos with vehicles on jackstands, dripping oil everywhere, etc. If they want to do it in their backyard, fine. In a public area... nope.
The crock to this entire ordinance is that "old" vehicles are considered "antiques" and you can park them anywhere you like, in any condition, with or without current tags/registration. When we first moved to Allen, our next door neighbor bought a '49 Dodge truck. What a pile of junk. Actually it had some potential, but they parked it almost right by my mailbox, it never moved, never ran, nothing. I called the city after about 6 weeks. They came out and said it was an "antique", so none of the ordinances applied to it. Uh, ok.