Welll personally I think there is something quite special going up in cub with only the minimum fitted.
Wet compass, no artificial horizon a few engine instruments and a window to look out of.
Its your cash if you want to hire an aircraft with everything working don't accept it if there are things broke. And when you phone up to book ask if it has been fixed and if they say no , just say thanks but no thanks in that case. Don't get stroppy and start quoting MMEL's and all that stuff just say NO don't want it.
Enough folk do that and they will get it fixed.
I can completely understand why a punter would get up set if an aircraft is being punted as IFR kitted out when in realitity its not due to snags. You pay a premium for it so it should work even if you are only wanting a VFR machine.
The only way your going to get owners to fix stuff is by refusing to hire it. Just make sure they know that they have lost a rental by running it broke. But if there enough people willing to hire it don't expect them to fix it.