High elo players don't communicate

So, today I played a normal game as adc and my support was Diamond V. My account currently stands at Gold 3 and I can say that I play with and against Diamond accounts all the time and this was one of the few bad experiences I've ever had. Basically, what happened is that my 'Diamond' support was ruining my farm. He wasn't feeding neither was he trolling, he actually played pretty good. He would auto-attack every creep when they were almost dead, when the ranged attacks from our own minions were already going towards it. To explain it better: the creep was almost dying, I had to wait for 2 ranged auto-attacks from minions and then I could last hit. He would attack the creep pretty much at the same time as the ranged minions, so that neither one of us was getting the creep... he was basically ruining the whole farm. I proceed to ping 2 times for him to stop, he kept doing it. I proceed to write in the chat "Please stop doing that". He didn't reply and he kept doing it. At this time his premade friend playing lee sin steps in and says "Let the diamond support". Seriously, what the hell ? I mean, I could even be wrong... maybe there was some sort of weird strategy in ruining my farm that I didn't know about, maybe he was trying to last hit the creeps or something, I wouldn't know - I'm not diamond. Maybe he knows something I don't, maybe (probably) he plays better than me and is trying to help me and the game somehow and I just don't get it - but why do people have to be like that ? Is it really that hard to type in the chat "Hey, im doing this" or "Hey, we should do this, that's why im trying to attack the creeps". Instead the player just proceeds to not communicate at all and ruining my farm and fun in the game.

I'm not simply ranting about this situation, I'm asking/advising high elo players out there to get off your goddam high horses and start communicating with your team. I guarantee both you and the rest of the team will have a better experience. I mean... hell, I've found bronze players communicating with the team and try to improve and become a better player, making the game a better experience... why do some high elo players have to be complete jackasses?

TL;DR: Some (not all) high elo players need to stop believing they are some sort of gods, better than everyone else, and start to communicate with the team.