single word requests - What would I call this 'attitude'?

A friend of mine has a bad habit of undermining people who are not the best in their respective fields.

If in a car-race, player A wins out of 26 players (A,B,C...Z). He would claim 'A' to be the best but then he would start calling all the other players stupid, pathetic, unworthy of respect heck! even a small appreciation and acts as if the other players don't even deserve to live on this planet.

In every competitive aspect of life, someone would lose and someone would win. That's the nature of the law. The person who came out as 2nd perhaps lagged by an insignificant time interval. He would start to worship the winner and would start calling all the other players as 'worst player' each (starting from B,C,D,E,F...Z).

There are only two categories: Winner(A) and losers(B,C,D...Z) with absolutely no distinction between, let's say player 'D' and 'V'. I would like to add that the field may be and usually is something which he knows very little of.

What do we call this attitude? I would prefer a colloquial word.

The sentence which I would like you to fill up would be:

Stop acting so ______; It's not okay to be so critical about the other
players.

If you have any alternative equivalent of this sentence, possibly humorous, do suggest. Thank you.