Why are there these kind of people in Normal Drafts?

Got to love playing with a team that the second you get into a game start with "(insert player name here) is gay" and then repetitively saying that throughout the game. Muting is good for one player who is like this, even the whole team if it's that bad, however that means if someone makes a call or wants to actually communicate with the team, either they're muted or no one is going to listen due to their current behavior. This happened to me where a jungle for some reason hated my guts because I was "gay" which then inspired the rest of the team to start doing the same. 30 minutes later, I lost a game with a 4 man team: ADC with smite of all things having over 10 deaths in less than 20 minutes, Support building , Mid that was pretty decent, and then our jungler who got the most kills. In the end, we have the enemy adc and support going "easy 1v9, we beat you guys while having s*x". My question is why are there still players who act like this playing?