If they followed the scientific method, which they did since this is a published article then it's definitionally not pseudoscience. It could be poorly carried out, biased, etc (I don't believe it is however) but not one lick of that would make it pseudoscience, it would only make it bad science.

I personally think that study into people's living conditions is incredibly valuable. It's something that impacts every facet of people's lives and better knowledge could end up generating huge improvements to people's lives.