@Riot: Are promo games intentionally rigged?

I find it very easy to raise my LP to 100 time and time again, but alas every time my team and I throw both games. I'm wondering if matchmaking intentionally places you with players that are more toxic, more tilted, etc. to test if you really got it? Because IMO Riot should place you in a lower bracket for promos and make the actual grind to get to them the tough part. Could a Rioter please enlighten me?