I bike in a city grid most of the time. Cars and cyclists are literally elbow to elbow at relatively slow speeds. I am happy to get passed with ONE foot to spare, much less three or five and would not want motorists ticketed for such anyway. I often split lanes with less than 3-feet on BOTH sides of me. So it's hard to hold motorists to a different standard, although it is a rare moment in the city when any car is passing me anyway. Just don't hit me and I'm good!
On the open road where cars are driving 50+ mph? Yeah, I would like a couple of feet for margin of error. But I quit cycling those places so it is no longer an issue for me.