No, that's not the reason. The reason is that people are visiting the sites in the late morning, or in the afternoon, because that time is convenient to them. Also there are only a handful of people that are actually bothered about the original intention of the builders - perhaps only a hundred in the entire country - and everyone else - those flourescent cagouled photographers - are just 'into the vibe'. In a way, experiencing these phenomena, with all the pain and tribulations of getting there, under the right conditions, is an initiation into (some of) the ways of the ancient folk. It's a pity there aren't more like-minded souls but the priestly caste has always been a minority! Watching the stuff on film (DVD) is just deeply sad ...