The thing is, the issues trickle down and the culmination isn't "The game isn't fun anymore." The issue is, people don't care to help those who are bringing them down. Bringing their mood down. Bringing down their morale. Bringing down their expectations that came from the status of the game. Bringing them down by buying outlandishly bad items in a situation where, with any logic, they have no right to purchase said item if they are really playing with the goal of winning in mind. Trolls come from performing at an OBJECTIVELY INFERIOR level - this doesn't mean they're bad, it means that they're having fun at the expense of their teammates. If League of Legends meta wasn't enforced, why do you queue for different positions, and each of those 5 positions MUST be filled? Duh. The meta IS freakin enforced. Surprise!
Blind pick is inherently awful because champion roles and selections get stolen. That puts people in a bad mood before the game even begins.
Normal Draft is going to bring rage because a lot of the time, players are practicing to get better in a pseudo-ranked setting, without the potential repercussions of their actions of failure resulting in loss of LP. You get bans. Playing against champions who have a high impact/winrate like the current monsters of the patch aren't fun to play against, so you can ban some of them. Additionally, it isn't fun to play against people who suck at the game. Like you can read them and just realize, hey this person is awful. This is why this match poses little to no challenge to my skill level and reducing the quality of the match.
Ranked Draft isn't for fun. It's for competition. You play ranked to climb and/or improve, and it's hard to improve in other modes because people tend to objectively avoid putting on their serious face and do what is needed of them to try to win the game. They are a sub-optimal beacon of weakness and inepititude-filled mistakes and decision making in an environment where sub-optimal choices, items, positioning, champion selection, summoner spell choice, etc is an act against the players' goal of winning the game. It's the equivalent of watching a Football game and a teammate goes for a catch but a teammate of theirs "playfully trips them" and they lose the game. I guess everything's okay as long as that guy had his fun.
So yeah, Sona, you rush that Infinity Edge, gank that Volibear, and solo Baron. Have fun!
See the problem with this video is that he's basing everybody on an equal standard when in reality that's not the case. Not everybody has the same mindset or the same attitude towards anything. Some people might queue up just to troll, feed, and laugh while their team rages. Some are hypocrites who will drop passive aggressive remarks whenever someone does bad but starts flaming and blaming the moment it's them doing poorly.
What riot needs to do to fix this game community isn't tell us to be "positive" they should enforce rules, they should actually monitor games, and they should punish players accordingly rather than just giving them a slap on the wrist via automated system.
You can be as positive as you want in game but when the top fizz is 0/5/0 7 minutes into the game and cussing you out for not ganking him I don't see how you can be nice to that and keep your cool/calm attitude.