Tactful ways to inform people that they're playing badly?

[RoyalBeef]

This is a video game some people play to relax after a hard days work, it's not a second job. The last thing they want is to deal with unsolicited advice, they deal with that all day at work. They don't want to deal with any sort of BS, especially not from a stranger they are unlikely to ever meet again.

Why does the "it's not a 2nd job" argument come up anytime someone mentions they expect partymembers to deliver an acceptable performance? Would you join a band as a drummer that's not even trying, and when they're like "dude wtf, play properly" you go "Nah I just do this to relax, I get people telling me what to do all day at work, so suck it up"...what? ^^ Then go play alone in your garage, don't ruin it for 3 or 7 other people.