I have that too mate, it's just the edginess in the age that people often play the most in what is due to natural reasons. Sometimes people have a bad day, some of them quite often it seems and internet is a easy place to show your worse sides even for undeserved reasons.
Not saying it's "only the young people", every age group does it, but the experience you gain in life usually makes you able to evaluate your input a bit more.
In those cases, especially when it's a team-wide mentality issue, just mute and play out of their plays with music on and chill. Prepare for next game and just take what comes.
Trying to carry everything and thinking of it too much will just burn you out. Albeit, I think that the "IWNL" mentality is a unevitable part of a player like f.e. s1mple. But all-in-all it is a journey to reach a goal, what ever you want to be and that match or those matches will be just a few matches out of hundreds or thousands. Don't think too much of it.