I have a 63% win rate on Morgana at the moment...
Some assclown dipshits looked me up on op.gg cause I didnt give them the tank support they wanted so they could find something to bitch at me about.
They started giving me a huge ton of shit because I have attack speed reds on with Morg sup. They start going "AD MORG" "GG OMG AD MORG" "GG" "GG" "GG" "GG." This is my teammates... I told them "If you can see my runes, cant you see my win %? STFU and focus on your sht."
So of course you know what happened with me having atk speed reds on Morg sup... we lost... no wait, WE WON! I got 2/4/18, in a 38/36/37 match and an S- on Morg.
Why did I type all that?
Rito wont fix these one sided stomps because they do it on purpose. For every match thats close I think "OK thats what match making should look like." Then for every match that is an ROFL stomp where we win way too easy I know Im going to have to support a Gangplank ADC, or a Soraka jungler, or my favorite BS troll nonsense so far...
Full tank 
Yeah. Had an assclown on my team building full tank Vig. mid. We lost. I mean at one point they picked up in damage, but well after they fed an enemy Yasuo and that Yasuo went ham on the rest of it making any contribution too damn late.
So where did tank vig come from? Ritos match making forcing a 50% win rate.
Its my belief that Ritos match making actively tries to stop winning streaks by injecting trolls, toxic ragers, and morons into your games. Those onesided stomps are part of this match making scheme. They match up people winning with people losing against people winning... till they decide to turn the tables and match up the previous winners with people on a losing streak.
So that Morg match I mentioned, that was supposed to be a loss... One of those people in the lobby was threatening to run down mid if anyone picked certain champions... The other one giving me shit went 3/11/9. Rito gave me the shittest odds they could with toxic ragers on my team that threaten to feed based on allied champ picks, and a feeder, while still having the MMRs be close enough to make it not a total joke.
Why do this? Some people want to climb as high as they can; for some that stops at gold for the rewards. Riot, like any F2P game company, wants you playing. If youre not playing youre not invested. If youre not invested, youre less likely to spend $$$.
Think of it like this:
Youre in a van on a road trip. The van was provided for free, along with gas and meals. But while driving youre subjected to advertisements. The more advertisements you see the more likely you are to buy one of those things you see. Those ads are provided by the same people who provide the van... Dont act surprised when the road trip takes 3 times longer than you expected because of all sorts of mysterious roadblocks and strange mechanical failures. Thats all to increase the ad time. They want you to stay in that van as long as possible.
TLDR; Rito creates lopsided ROFL stomps as part of their forced 50% winrate match making system. Dont expect them to fix a system they put in place thats part of their method of $$$ making.