I think its a slight case of unexpected or odd events getting peoples attention(but not completely unwarranted). You see 10 deer in the morning or evening and that is normal. You see 10 at noon and it stands out in your memory.
The trail camera picture is a good example. You probably have a 100 pictures of deer moving morning and evening for every one you have at noon.
Deer will move all hours of the day and night for various reasons and hunting mid day could certainly pay off but if I have 4 hours to hunt on a given day its going to be morning or evening.
I'm also the opposite of one of the other posters. If the herd moves through at 7AM I am less likely to hunt until 11 AM than I would be if I hadn't seen the deer move yet.