I do dust off my bikes after ever ride, wipe down the frames and do "try" to keep the drive train semi-clean. We have "grit", everywhere, especially in the Bike Lanes here in CO. Spgs., it seems the sweepers like to clean for the cars and dump the crap in the lanes for the bikes, arrrrrrrugh!
Still, I DO NOT OWN A CAR so my bikes get ridden "every day", unless there's ICE on the roads so I can't keep them, "pristine clean" as we live in a 3rd. floor, 1 bedroom apartment with NO outside water source.