I've been running car tires on my bikes (rear only, of course) for decades. I first encountered it back in the mid 70s. We'd put VW Bug tires, 145s or 155s on the old Harleys and Indians we were riding in those days. They didn't work as well as today's car tires, but they were superior to 1970s mc tire technology for our uses.
These days, the only time there's a bike tire on the rear of one of my bikes is if I bought the bike that way and haven't worn it out yet. Or if I needed a tire on the road, and there was nothing else available.
Here's a shot of my last bike, a Suzuki VS1400 Intruder:
The tire is a Kumho PowerStar 758 in 165/80-R15. A steel-belted, radial car tire that cost about sixty bucks, delivered. Front is a Metz ME880, if memory serves. Look at the tread depth remaining on the rear. Hard to believe it's got almost ten thousand miles on it. 8)