Remove safety pip
One good way to fix the ranking system would be to remove the safety.
It is almost impossible to get deranked by a couple of bad matches.
Which actually should happen.
If you perform bad at the current rank, you should get deranked,to your own good.
You -or me- don't belong at that rank and constantly having bad matches and ranking up anyway is not "fun".
Right now losing a pip is really rare, while gaining a single pip is pretty common. So basically anybody can rank up as long as he plays enough matches.
If the removal of a safety pip blocks someone from ranking up, he should stay lower anyway.
I myself would still rank up, but I would get slowed down and could enjoy the game longer, because I would stay away from the toxic high ranks longer.