Interesting theory but the .gov won't "outlaw" existing cars. If this happened they'd just let them go away gracefully. Most people go to mechanics to get their oil changed and those that don't generally take the oil to be recycled (eventually). I doubt very much ends up in the water table because people are too damn lazy to recycle it - if they're that lazy they wouldn't be changing it themselves. I probably have 20 quarts of dirty oil in my garage but I do take it to the local trash dump, which has an oil recycle bin, about once a year.
I'm a car guy but I'd love to have this system, assuming it's able to do an effective job of not keeping a lot of dirty oil in the system. I would imagine that even if it did keep some, it would dissolve into the new clean oil enough that it would be negligible. I change the oil on two of my cars because I just don't like quickie oil change places (I find them a hassle, I hate waiting, and I hate trying to be upsold on every little item - just change my damn oil) but I certainly don't love getting under the car so if I could swap everything out in the AutoZone parking lot, that's be fabulous.
You sound exactly like myself.
The packaging is the issue. Usually you need to lube your arms up with Vaseline to do any work in a modern engine bay. That cell takes up a battery sized portion at least.