I think that there several reasons, at least. One is as you said, 'stuff changes' roads fences housing food/water sources and deer simply change their habits. Areas for many reasons loose deer populations.
One, I believe, is that those 'good stands' get over hunted. I know that deer don't talk, as you say. But if there is constant activity weekend after weekend out of one blind I believe deer become blind shy. Maybe only hunt that stand sparingly. in Texas our season is, basically, from the first of November through at least December. In that case only hunt those 'good stands' the first weekend, Thanksgiving weekend and Christmas/New Years week.
capt david

"It's not how hard you hit 'em, it's where you hit 'em." The 30-06 will, with the right bullet, successfully take any game animal in North America up to 300yds.

If you are a hunter, and farther than that, get closer!