Earlier quoted context omitted.
It indicates distaste of the phrase, in eyes of the author I assume. I personally don't like "no worries" either, mostly because I'm a very literal person and words that unnecessarily imply things bother me (ie someone who's thanking you is rarely worried about the matter).
I took to "no worries" fast when I was in Canada because the intensity of the thanks you get for minor actions in North America was overwhelming for me at first (before I realized it was a nice façade that helps smoothing the social rapport). I remember my first few days working at a tech shop in the suburbs of Vancouver, I made a pot of fresh coffee and told one of my colleagues so that he could get a cup had he wan…
I see. My response in that kind of situation would be one of: "sure thing", "don't mention it", "sure", "my pleasure".