Originally Posted by RustyC

Tourists aren't created equal in terms of footprint, and while so many places want to attract the big spenders, those same people also tend to have the heaviest environmental footprint. It's also how you get pressure to offer helicopter rides or all kinds of vehicular transport depending on the site. a badly-run flight-seeing Grand Canyon trip could degrade the experience for hundreds on the ground, for example. National Parks have long ago figured out that in most cases it's not too many people, but too many cars.

I'm also no fan of cruise ships because of the yo-yo effect in terms of people it brings to the less-populated or more-fragile places.