I give hatch out of pity, i.e 3 people with the collective IQ of a can of Spaghetti-Os and a decent carry, the decent one gets hatch.
I give the hatch quite often, I'm not really a tryharder:
3k, 4k... doesn't mean anything, there are no tournaments, no rank rewards, so what's the point of tryharding so much? With 3k I pip anyway, so last lucky survivor can have some bonus points from me. Sometimes though I close the hatch and give them the gate. If you'll ever be last survivor, looking for the hatch and spot a Ghostface, 'teabagging' the hatch, closing it and then coming at you, 'teabagging', then don't be afraid, I most likely turned 'Scary Movie Ghostface' mode on and you can safely go for the gate ;)
Tf is wrong with ace, him and ace are usually the most friendly survivors
I only give hatch when someone DCs early in the game or when every survivor I killed was a potato and the last survivor was a good player.
Kind of not true to my answer but I do if they were respectful to me, which is rare these days.
One recent game reminded me of another reason. The Hag caught me at the end. Two survivors just cowardly run, abandoned me, although there was still a lot of time to do something. Last broke the Noed and saved me and get hooked instead of me. I decided to give my life for him, for his boldness. Saved him and was downed. He managed to escape from her. Hag picked me up and just carried me to the gate. Reason - for selflessness.
I sometimes give the survivor the hatch but it's not as often as I did last year. Sometimes if I feel like I earned it then I'll take my 4k.
Mainly the reason I kill the last survivor is for the points. If I could get max points before the hatch spawns then I'd probably let the survivor go.
There is times when I give hatch, If the best player I've seen survived longer/finished objectives better than most survivors and also is the last survivor alive, I would give them hatch, because I understand when you try your best but get easily flawed by the random players you have.
While I get what you mean and it is a very fair point I did actually see it happen once, this smurf squad I was with felt bad that they bullied a baby hag so one of them let herself get hooked when the gate was already open, even I gave that hag 2 hooks mid game. I think part of it comes down to survivors making 5000-6500 score for escaping and killers make like 600-800 something for a kill.