@ RIOT - Matchmaking

I recently have returned to the game, and have been playing again for about a month. My ranked rating is low gold, and i haven't played since way earlier in the year. The problem I'm encountering is that i keep queing into normals and playing against teams that have 2 plats and a diamond, or a diamond and a plat, while my team has 3 silvers. Now you could discredit this as a random complaint but i have screencapped over 10 instances of this, and the MMR difference of my normal games over the last 20 games has an average of -250 MMR. Thats absurd. Its demoralizing. And its downright not fun to play the game. Is there any reason i keep playing against 1600+ MMR teams when my team is never above 1400 MMR? Has riot said anything about this? I'm honestly about to quit playing again cause its just not fun when your team averages a death per minute in a 20 minute ff.