You are overthinking this way too far
In sprint racing you are almost never racing against the entire field. You are racing against the few people in front (if any) and few people behind you. If an amateur rams me out of the track in turn one (there is a difference between ramming and trading paint), then I have nothing to gain from staying in that race. I'm not going to race my way up and experience the same again from the same amateur driver. It's better for my personal experience to find another cleaner race.
Also, if GT Sport were more simulator and less arcade, both the rammer and I would have been out of the race because our cars were damaged. In other words: it's actually more realistic that people rage quit when they get rammed off track because we are out of the race either way.
I don't care about anyone else's feelings about me quitting from a destruction derby ... Luckily for me, it's
way less destruction derby with the rating I have now (although there are a few S-rated drivers that for some reason don't know how to drive).