Anyone have constructive criticism?

So, how many times have you gotten tired of practicing on bots and decide to try out a new champ against real people on normals, only to be verbally assaulted when you feed or are generally performing poorly? Its sad that so many people in the community default to "WOW ur bad, stop feeding!" instead of offering genuine advice on the champion you're playing and how to do better next time. I doubt this is how people think, but from what people often say, it sounds like they believe that by insulting a teammate, said teammate will magically transform into a diamond ranked player and carry them to victory! I understand Riot already has multiple systems in place to rectify poor behavior and promote cooperation, etc. but still these awful experiences remain. Yes, I can read up on boards, forums, guides, videos and everything else to become better with a new champ, but eventually I need to play against actual people and it'd be nice if my teammates helped me get better too. It really sucks having a couple poor games in a row, in addition to having really rude teammates make the experience even worse. Some days I have to just walk away and do something else because I know in my gut the next couple games (most likely) won't make me feel any better. Sorry to vent on the forums, but I just want to know if anyone else has experiences like this? For me its pretty much the worst part of an otherwise spectacular game.