I once had a similar idea.
When I first started playing ranked matches, I broke 1400. Life was good. I was on the up and up.
I was down in the bottom of the 800's, couldn't find a decent team for the life of me. Every game I got in was nothing but trolls or baddies, and they were all dragging me down with them. Game after game, I was lucky to win 1 out every 5. I just couldn't carry hard enough.
It took me about 70 games holding steady in the 800's before I started to understand that I deserved to be there. It took about 30 more before I started to understand enough of how this game works to find a way to improve my game - to make myself enough of an asset to my team to warrant a higher elo. It took that long before I started being able to CONTRIBUTE my fair share to a well-deserved win.
Sure, you're going to get matches where someone leaves, but that's going to happen on both sides, and it will even out. Sure, you're going to find amazing teammates who want every other role except your best, but you're also going to find teammates who demand your favorite role. And guess what? That's going to happen to the guys on the other side just the same. It will even out. If you play enough matches, you'll also get the opportunity to play both with and against someone WAY better than everyone else on the team. But keep playing, and it will even out.
The only thing that doesn't even out is you. You will ultimately reach a point where you contribute just as much as everyone else in the games you're playing. You'll know when that number you keep watching so intently bounces around a bit, but doesn't really move much. There's only 2 ways from there: Contribute less, or get better so you can contribute more.
What you're proposing is a way to undo all the work you put into your elo. You say the only people who could abuse it are the high elo players, but they could just dodge their way down to whatever elo they want (and some of them do!). But I keep thinking of the people who would want something like this. The me of 300 matches ago. Let's say I shelled out money for a reset. Thirty matches afterwards, would it have made a difference? No. Now I spent money on something and got nothing out of it. Where's the value in that? All you're doing is bringing money into an issue that's already rife with contempt. When did money ever make any situation better?
I'm a 1200 elo player now. I'm damn proud of that fact. Because I know I USED to be an 800 elo player. I got better. I started filling in roles we needed. I bought wards. I bought oracles. Map vision is important. I got better at last-hitting, advanced my lane control. I started understanding counterpicks. I learned that sometimes you have to forsake a lane and focus on something you can actually win (like bottom lane). I learned not to roam when you've got an exp advantage to lose.
There are some matches I lose where there's nothing I know of that I could have done better. There are some matches I win when I know I did nothing right. Elo hell exists; it's that range where everyone blames their losing on someone else. You're trying to buy your way out of something that we take pride in earning. You're doing it wrong.