While I have not been to Bhutan (though I would love to go), I have been to Nepal. I spent two or three weeks in the country, and most of it was in the Himalayas at a small village called Pangom in the Arun Valley. I knew the area was remote, but there's nothing like being there to really drive that home. There were no roads whatsoever. We had to be helicoptered in to the site and picked up at the end of our stay. Our gear was transported by these strange yak/cow hybrids escorted by Sherpas who walked for days to get anywhere. When tensions with a neighboring village arose and police were needed (Bobo was accused of angering the gods and causing a torrential downpour and the resulting landslides), they had to walk from a nearby village downslope and it took them over 12 hours to arrive.
Not only is this area huge, but the terrain is extremely rugged. The mountain slopes are ridiculously steep and covered with leech-ridden semi-tropical vines with pokey thorns and worse. The people who live there mostly lack electricity. They live a subsistence living by catering to tourists "trekking" through the mountains and by growing potatoes, cabbage, and other crops. Most of the folks who helped us were illiterate.
Ranae spent a week before filming in Bhutan and she reported that the situation there was more or less the same in economics and geography. I feel that my assumptions about Nepal would largely be accurate to describe Bhutan as well.
To me, it's a wonder we hear of ANY yeti sightings. The people of the Himalayas are far more preoccupied with surviving than reporting sightings to outsiders of animals they know live there. Most of the mountain folk know people don't think yetis are real, so why should they care what scientists think unless they can make a living guiding for them, or being porters? They go to bed at dark and wake up at sunrise. They aren't out in the woods at night. They are wonderfully simple, happy, and compassionate people living a small life in a huge mountain range. Who would they report a sighting of a perfectly normal animal to, anyway? Even better, HOW would they report it (it's a two-week walk to Kathmandu)? I imagine such an action seems like quite the hassle to a Sherpa trying to put food on his family's table.
Just because Westerners don't hear about yeti sightings much doesn't mean they don't happen. I have to question whether or not yeti sightings are in fact in decline, or have remained more or less quietly steady over the years. Just because a news article says so, it doesn't make it true.
Just my two cents from having actually been to the region.
If you're interested in reading my field notes from Nepal, they are posted on my website here:
http://cliffbarackman.com/finding-bigfoot/finding-bigfoot-episode-guide/finding-bigfoot-season-four/finding-bigfoot-season-four-abominable-snowman/
Cliff