Why do players give up when the battle isn't favorable?

I haven't posted in awhile but I have still been playing Helldivers 2(PC), Space Marine 2(PC), Monster Hunter Now(Phone), and some other cooperative games. I've been matchmaking and get paired up with randoms who I think are in it to win it.

They're not. They only stick around if the mission is going smoothly and without hiccup. The moment things start to go bad or it looks like we may have to reset, they leave.

No second chances? I don't understand. It's not like we're given negative points or detrimental effects and it isn't even a hard loss. Usually there is still a chance to comeback but instead of having to struggle to eke out a victory, 'Player has left the game' fills the corner of my screen.

Games nowadays will still give rewards for defeat, even if they are minor, so there is a reason to continue playing but these players seem to only want the 'unbeatable' feeling of stomping the enemy to the ground. Maybe they see the tiniest setback as a blemish on their whole gaming career?

With one player down that chance to comeback falls to almost 0% because not only do we lose a teammate, but now that 'Player has left' notification makes the other team mates lose their morale/fervor to play at their 100%. It's a domino effect that has made a slightly unfavorable battle turn into an impossible mountain to overcome.

A player leaving because they aren't doing well or the fight isn't going as planned hurts the most when the battle is at that critical moment. The team needs everybody on deck in order to ride this wave but suddenly there is slack on the line as a player disconnects.

I think seeing the mission/match through to the end is respectful of every ones time and allows the player a chance to see why they really failed in a match instead of 'Well we lost because one player left and we couldn't make up that missing number.'

This post might be a personal gripe but I also think it makes sense to finish the game no matter the circumstances or eventual outcome ingame.

Stay on the objective and stick with the team! Players life expectancy are usually longer and the outcome will definitely be more favorable to achieve victory

Thank you for reading.