Preseason Ranked Placements

WHILE READING THIS KEEP IN MIND I AM NOT RAGING, BUT WONDERING IF THIS IS A FAIR SYSTEM! IF YOU THINK I AM WRONG FEEL FREE TO HARASS ME IN THE COMMENTS!

I was wondering how placements are "fair". I was in plat last season, I did well in a majority of my games outfsrming my lane opponent and being overall smarter than them. Unfortunately I was matched with (and against) people in silver (I was plat in s6). Seeing as how I don't have a super aggressive play style, I usually just make picks and trade until a gank. Sadly, most silver junglers don't know what they are doing which results in me going even kill wise and not being able to transition my lead to the rest of my team. At the end of the game my team will have an afk due to rage, someone who doesn't have a brain, or someone who uses a trackpad (aka they don't know what they are doing). I like to play late game hard carries but some games end before 15mins (gotta love the 3 man afk tactic). I main adc but find it hard to play adc because my support is an idiot 90% of the time. If you have any suggestions (the only one I can really think of is have a 3q with other plat players). Thanks!