It takes one loss to get you demoted, and three wins to catch back up
So you just get into a new division. Well you lose your next match and get demoted. You just lose, and get sent back. Now you have around 70 LP, and you need 100 to qualify for a series. You win your next match. Now you have around 95 LP. You win your next match. Now you're qualified for a series. You win your next match- and you're placed into the next division at 0 LP.
There are no "loss divisions"- you don't reach 0 LP and have a match to determine if you should be demoted.
The ratio is just too extreme. You lose LP at an incredible rate. I've went 6 matches all victories, and got it all set back by 2 losses. Why even bother playing at this point? Why work hard to climb up in the ranks if a single match can erase the progress of hours of gameplay? If I go 5 games without losing, I've only earned around 60 LP. If I lose my next match, it can drop down to 20. And if I win 4 straight games after that- I'm at 50 LP. Now my W/L ratio is 9W-1L, a 90% win rate: and I'm losing LP.
If a person is winning 9/10 of their matches, they shouldn't be getting demoted.