When can we fight the real balancing issue?

there is no way to stop them

YES. THIS.

Anybody using smurf accounts more than a tier higher than their main account (diamond using bronze, plat using silver/bronze, etc) should have all their season rewards pulled and their accounts banned from ranked, PERIOD. I know a few people who have been "helped" along the ranked path by people 2 tiers above them that carried them, but its pretty much a legal thing. Then there's stories of those who have people 2 or 3 tiers ahead make an account that's unranked or bronze V and suddenly go 25-0 and win game after game. Why the hell isn't this punished?

The other day I was up against a Master Yi who had over 25 kills in just a teambuilder game. This guy was tanking 4, 5 turret shots with no armor, no points in W (I checked his build/runes/masteries post-match) at early levels and just steamrolling. I was one of the two who killed him, and then afterwards I looked him up and found it was.. his first game?! Yeah right. NOBODY builds the way he did and plays the way he did and levels up the abilities in that manner unless they were a really good Yi player who made another account. Now imagine this kind of situation happening in ranked... and you not only can lose but be DEMOTED because of it? Complete bull.