Yep, but if you climb to Gold then you're a "tryhard" in the eyes of all the trolls.
Agreed. People need to approach their play style as seriously as they do live. At least in ranked. Normals is normals. It's always flush with trolls and that'll likely never change.
As to the AFKers and the like - there's so many people on PBE who are not from NA servers - they often have atrocious connections. Now - granted these people shouldn't play ranked, but as Riot states often - PBE is for everybody. Thankfully, PBE doesn't actually matter per se - your rank could be reset at any given point in time should Riot need to test something or do a total server reset for some reason. That's no reason to not advance, though - as higher tiers need testing as well to ensure the ranked system is working properly.
TL;DR
OMG Trolls!
Hey, you're from Indonesia? That's cool. Don't play ranked plz thx
Your rank can disappear at any moment, but it's important to have people at those tiers to test the tier system.