You are a good example of the word "provincial." Unlike you, I have hunted a wide variety of big game, not mostly deer, and have taken plenty of others at 50 yards or less. (There are seven legal species of big game other than deer just in Montana, but also travel to other places quite a bit.) Just went through my hunting notes, and found I've taken 13 other species at 50 yards or less, ranging in size from under 100 pounds to around 1500, including Cape buffalo and a grizzly.
As for 6x scopes being a poor choice, much of the myth that 6x's too much for closer shooting appeared when scopes were much "skinnier" than nowadays. The major factor in field of view is the rear (ocular) lens, which is essentially the "viewing screen" in scopes. In older 6x scopes it was very narrow, but modern scopes have much wider oculars. The typical field-of-view for new fixed 6x scopes or variables set on 6x is at least 20 feet at 100 yards, which means 10 at 50 yards, and around four feet at 20 yards. Since the front end of even the biggest whitetail or mule deer isn't more than four feet tall, this means there's plenty of field of view to make a 20-yard shot--or closer--IF the shooter is reasonably well-practiced with a scoped rifle.
Unlike you I have killed many deer at close range in heavy cover with a wide variety of rifles and scopes. Not sure I'd be giving advice on what works best there if I'd only taken 22 total at less than 50 yards and 3 at less than 20 in 56 years with a limited variety of armament. A reasonably competent hunter could easily rack up those numbers in 10 seasons here and a good one might well do it in five. Multiply your sub 50 yard totals by 6-7 and you'll be getting closer to my neighborhood. In fact I have killed 6 inside 50 and 3 inside 20 in just the last two seasons and I missed most of last season due to illness leaving 4 tags unfilled as a result. Like I said before, my experience may not be wide but it runs fairly deep. Oh and BTW, I do have a modern 30mm variable and the field of view at 6x is still less than I want for those sub 20 yard shots which occur for me pretty much every season and often multiple times per season.
