What is the cause of this cultural difference between Deadlock and Overwatch?

In Overwatch, it is pretty common for people to stop shooting and have a moment when something silly happens. Like if a mercy gets hooked deep behind enemy lines after her whole team is dead, everybody might stop emote for a moment just to acknowledge the silliness of the situation before killing the mercy.

This never happens in deadlock. Even if a game is completely over and a team has several leavers, everybody will still aggressively hunt down and kill the remaining people even if they are just chilling in a corner. No time to hang out.

What do you guys think is the reason for this cultural difference?