If you read deeper into the story, they are promoting their kind of life-style as being a preferred method.  That is one of the reasons they agreed to the story in the first place.  Here is the relevant quote:

Their treks are made not only for pleasure but on behalf of Ground Truth Trekking, the nonprofit group they founded. Through this organization, the couple hope to raise awareness of environmental issues across the state by visiting contentious sites like the Arctic National Wildlife Refuge. They also consult for environmental organizations and run Sundrop Jewelry, an accessories business. Though their combined yearly income is around $25,000, the two say that their living expenses are slightly more than half that.

The website to their NGO is pretty illuminating too: Ground Truth Trekking  I think it is kind of disingenous that they set up a non-profit to essentially earn a living tax-free.  I wonder about the legality of it too.

My reading of that is that they are promoting something by their treking, not by their choice of living in a structure without running water.  Their treking seems to be their "line of work", and what they're promoting seems to be quite mild to me.

I guess I'm not really bothered by people who want to live their life that way, even if I think it's overly eccentric.  As long as they're not trying to tell other people that it's the “right” way to live, or trying to do it on the taxpayers' dime, I just accept it as part of the strangeness that makes up our world.  However, I do see the irony that you point out by the fact that they've denied themselves the most basic of human comforts….except the internet.  I guess it's proof that the term “luddite” doesn't apply to them. Perhaps an internet connection ought to be included in the new list of human "needs", along with food, water, shelter, clothing...  ;D