Hmmm. I can understand why this is so frustrating for you, despite not having played before myself. Its not exactly ethical to rage quit, especially if its for this small reward and nothing more. I understand why many people rage quit though, they get mad just because they are either a) not doing well or b) they know they're going to lose so they purposefully disconnect so they supposedly "dont lose" and because they dont wanna be humiliated from a loss. Of course, none of these reasons make it ethical or right in any way, nor do they give the person a valid excuse. Nintendo had a banning system on smash 4 to keep people who do this from getting away with it for too long and minimize trolling. I hope for them to do the same with future games, as well.
I completely understand why you call this being too friendly though. I dont see anything kind or ethical about rage quitting myself. I actually see it as unsportsmanlike conduct, and if you think about it, it may even be considered trolling to some.
If its frustrating you too much, id suggest playing with someone you know instead of random people to help minimize the issue here on your
end (if that makes sense). At any rate, the only other option you have
here is to just stay away from the online if the problem is too widespread or what not. Unless this is an online game, that should be an easy solution. Again i have not played, im only trying to address the issue to you as best i can and see if i can help here by explaining things to the best of my ability.