What causes someone to be a leech?

I know so many guys I have played a lot with in the past, or just started playing with who are super experienced players and they will just consistently ask to join a day or 2 into wipe, and aren’t even willing to farm some wood. They get bagged, grab a kit and will instantly go pvp. Then afk if anyone says let’s do a farm run. Or the guys who start wipe, and then afk until we get guns. What causes this? And why are people like this?

The best players that I’ve played with aren’t just PvP chads who never farm, they are PvP chads who also are extremely efficient farmers. When I play in groups with them, if there are 6 of us, we have 6 times the amount of resources. When I play with some of the players mentioned in the first paragraph, we have 6 players and half the resources because only 3 of us farm.

Just don’t understand how this mindset of no farming develops. Just ranting, would also like to hear some other opinions/thoughts.