What is the principle of giving a ban for 15 minutes? (Rocket League)

What is the principle of giving a ban for 15 minutes?
I always try to finish any match to the end and lose with dignity, but I see that opponents in 70% of cases come out when they feel defeated.
But there are times when the balance of the selected players is generally inadequate, or some scum who scores goals for himself gets into your team and you can't do anything about it.
So, after one such match, I went out and got banned for 15 minutes. After that, I generally thought that it was given for every abandoned match, so don't go out and finish playing until the end, even the matches, I was left alone against three players. Then I was in a hurry and left the game - there was no ban. Then there were such cases - also not. Today we also played and the balance of power was generally crazy, besides, there was some kind of disabled person in the team. We decided to go out to play a normal game and the second time in the whole time was banned for 15 minutes. So what is it for and when to expect it?