Your Twitch viewership may be low, but that's no reason to allow the toxic ethos of smurf streaming.
A lot of your Twitch viewers and streamers could very well be smurfs of some kind looking to hit it big, but the cost to you and your player-base is much higher than you'd like to admit. It has people quit. It has people feel like they've wasted their time. It has people thinking that this kind of toxic and/or unsportsmanlike behaviour in the ranking ladder - a supposedly professional, tournament-like environment - is acceptable.
I implore you, Riot, start banning and/or punishing people who create smurfs just to stream them stomping people several times lower in rank, because it really is not healthy for your game or P.R. It might even alleviate some of the rampant toxicity that's been spreading around.