Well, that depends. How much are you saying they would charge for the Ice Wall trips? If everyone in the US went (301,197,000 in a recent estimate), and they charged a hundred dollars per trip, it would still only be about $300 Billion dollars, and that's of course over the course of years, probably. After that, you pretty much lose business. Who would want to go to see the Ice Wall a second time, anyways? So basically, instead of getting a crapload of money from tourism at once and then profits dwindling, they keep the profits at a standard which is INCREASING. That makes more sense to me.
Also, you must have missed the point of other factors which can play into it other than money.
~D-Draw