I think it may have more to do with WHERE you hunt, as to how skiddish the deer in that area are.
In my part of the country, I hunt in pretty much 3 counties. Pushmataha , Leflore, and Pittsburg counties in Oklahoma. I have noticed that in Pittsburg county, that has a lot of farm land, and a lot of cattle, as well as a lot of tree cutting, that the deer seem to be a little less apt to run at the first smell of anything unusual. The population here is around 45,000 people covering about 1305 Sq. Miles or about 35 people per Sq. Mile.
But in Pushmataha county, where the population is only 11,200 people scattered over 1395 Sq. Miles or about 8 people per Sq. Mile, the deer will break and run at the first thing that doesn't smell right to them.
Leflore county has 45,893 people over 1589 Sq. Miles or about 32 people per sq. Mile.
From 50 years experience hunting these three counties exclusively, I can truthfully say that the hardest deer to hunt come from Pushmataha county. They just don't see as many people, and the various scents and noises that they are around everyday aren't as numerous as in counties that have a lot of daily activity from farming and ranching.
Deer will eventually get used to about anything that they come in contact with, and quickly figure out what to be scared of, and if it does not create a danger for them, they will put up with quite a bit before leaving. I've seen deer feed around a drilling site and act like the noise doesn't bother them at all, but when a deer is not exposed to these differences in their environment very much, they will be gone at the first sign of something unusual.
I have probably hunted all three counties as equally as possible, and I always seem to have a lot more success in Leflore, and Pittsburg counties than I do in Push county.
Just my humble opinion. Does it make sense to you guys?