Have you ever actually seen one of these creations in the wild?
I think oil usage is a non-issue if the engine rarely runs, and flat tires don't happen if they're not ridden. Loud exhaust pipes, likewise, don't irritate anyone if the engine is off.
You can also save few pounds and the aesthetics of having a battery someplace, if you never need to actually start the engine.
It's about the satisfaction of a piece of artwork, not about function! LOL
(Sorry, maybe my response belongs in the Dissenter's Paradise)