IIRC NTS have put a sign up along the path in to the Hidden Valley in Glencoe to warn of the narrow path and steep drops. I think there was talk of putting a sign up somewhere in the area around Clachaig Gully - maybe at the top, to dissuade people from trying to descend the steep and very loose path on descent from the Aonach Eagach (I found a lengthy discussion about it here - note the reference to a sign that used to be in the Am Bodach car park at the eastern end of the ridge which is where most folks start from; I have a feeling that Hamish MacInnes might have been responsible for that). Although, people who regularly go in to the hills are agin such things proliferating willy-nilly.
A pal of mine married an American lass while he was working out in CA. Soon after they arrived they went on a trip to the Lake District. She was astonished to discover that there wasn't a waymark or sign post at every trail junction in the fells (and that's despite the Lakes being, I'd guess, one of the most heavily signposted upland recreation areas in the UK).
I believe that one difference between the UK and other places is that our hills tend to be largely denuded of trees so you can generally see where you've come from, where you're going, and which bits might be best to avoid (weather allowing). I sometimes find hillwalking on the continent quite claustrophic compared to the UK because, until you get above the actual treeline, you spend so much time following trails through large expanses of dense forest with no real idea of where you are without reference to a map and waymarks (I actually think that GPS can be more useful in such areas than on the Scottish hills, given good visibility.)
As far as remoteness is concerned, distance is not the only factor. Going back to the Aonach Eagach: you may be able to see the road from the ridge, but you ain't gonna to be able to simply jog down to the road if something goes awry part way along the traverse. And "going awry" can simply be someone getting cragfast on the scrambly bits.
Distance-wise, some of the Munros are pretty remote. A'Mhaighdean is generally accepted is being the most remote - the walk in from Poolewe is given as 22.5km in the SMC book. I've not been up there, but I have done Seana Bhraigh which was quite far enough thank you at a round trip of over 25km. Up in the north-west, although it's not as spectacularly hilly as the begging honeypots, there is some very remote country: mostly flat and very boggy (which is why folks don't tend to go there) but often miles from anything resembling civilisation.