Overall majority of players should stop thinking of their win/lose ratio (it doesn’t show anywhere albeit being recorded: who cares, no e-penile enlargement kit usage available) and just go with the flow.
I attempt to follow a way much like this; I don’t mind even if there are 3 bottom scoring Vaselines or anything such in the team, I just screw it then and pick a fun merc or set myself a melee-kill goal or something silly. Usually these deadweight players don’t care for the course of game either, they want to learn ins-and-outs of the class. But if they start going “defuze defuze nub tiim” etc. in the chat, that’s the moment to point out how about them trying something useful if they’re honestly having the itch to win. I don’t see any wrong in trying mercs in pub settings, that’s the way to go actually. Albeit some peeps should realize when to just try something else…
For me a simple “Oh I thought we were just goofing around and not tryharding since there’s so many people not doing their class jobs and picking completely unnecessary mercs to begin with” sentence usually works. If they insist on raging and blaming after that, it’s mute time and forget, those fellas are beyond help.
TL;DR: Gaming community has to start dropping the “free win or switch server” mindset. Starts with you. Yes, even you who don’t even think in such way at all. Educate those people. With bullets. In the face. No, wait, with well constructed, short arguments. I don’t judge though, I’m still in process of detailing such catchphrases myself too. Nothing wrong in urge to win, there’s just time and place for that, and after all winning is not all there is to having a good game and entertainment.