Some people find motivation from working in those kind of extreme circumstances. Others might find it from making money or perhaps the location of the school is importance to them or maybe it's something else. There are infinite reasons an individual might choose to work somewhere and they can't be fully appreciated by anyone other than the person who made the choice.

Just because someone chooses to work at a TC or in any other place that you wouldnt necessarily choose to work in doesn't automatically mean they are a lesser teacher or indeed that they don't derive satisfaction from what they are doing. You can't possibly be sure of those kind of things. There are far too many self verifying theories floating around this board.