I think it's an internalization of the "It's always okay to ask" mentality, which itself is a symptom of a transition from a society built around a few common cultural institutions to one based on a pluralistic conception that different people may have different values. It used to be that there were common norms of behavior, and you didn't step outside those norms unless you wanted to risk strong social censure. Now, the norm is that anything mutually agreed upon by two parties is fine.

On the whole, I think this is a good trend - it makes the economy more efficient, it encourages people to celebrate diversity instead of shunning it, and it's how the upper classes have operated for a long time, which is the source of a major power imbalance where corporations & rich people feel entitled to ask for anything and then working-class people feel ashamed to refuse. This is just the same attitude filtering down to formerly middle-class people, likely fueled by desperation as the traditional social compact breaks down and their previous income stream dries up. It'll take a period of adjustment as people realize that "No" is a perfectly fine answer that you'll have to give the majority of the time, though, and many people are very uncomfortable at the breakdown of unspoken norms (hence the article).