It's probably due to the fact that frying, held in the beeffat that is mixed in the ground deer meat.Alot ofpeople thatdon't know how to grill correctly, don't Sear meat on the grill when they first put it on, they flop it on, grill on one side then the other, It makes a world of difference to get the grill good and hot, put aburger on one side fora minute or so to sear it then flip it and do the same then reduce the heat to finish the cooking, It will make for a much tastier/juicier burger.
I agree with most everyone else, Meat and Fire are the only way to go, I have fried deer burgers, they are good, but to me just not quite like the taste of some good grill marks.