We get snow and rain here, so vehicles come in shop and garage with snow and water dripping off. We slope the floors towards the door and it runs out for the most part. Several neighbors have drains and hid the drain during inspections. They are also the same folks that think nothing of letting spills (oil when changing oil, etc) go down the drain. I rather properly dispose of my fluids and put up with not having a drain for the water to drain away. I am not a fanatic but do know where my well water comes from.
I have no issues with the water draining somewhere along with incidental other fluids....
You must make a distinction between Sanitary Sewer Systems and Storm Sewers, the codes do. No utility wants oil or anti-freeze coming into their digester. They have enough problems with the detergents and other household chemicals killing the bacterial action.
Out in the county no one wants chemicals, and oils in their septic system or getting into their water well either but since vehicles are not required to "wear diapers", yet, leaks of all kinds get on the streets from parked and cars in traffic as well as tons of salt, cinders and dirt that is spread on purpose. This stuff all washes into storm sewers or off into the ground. Large parking garages and commercial garages are required to have holding tanks for their floor drains in many cities. It is then often pumped out into tanker trucks and spread along country roads to keep the dust down or many times dumped near a river or stream.
I doubt if many people that are not allowed floor drains in their garages collect the mud and oil laden kittie litter into a specially marked bag and take it to a chemical collection center.
Folks that own land in the country usually have greater respect for the environment and protect it much better than the
folks that rent some space in the city.