I'm assuming the author is from the US. Convenience stores in Japan (and Taiwan) fill a niche that's desperately missing in the US: they're actually convenient. I can't get good tasting, cheap, fast, not-unhealthy food anywhere in the US. I'm not saying it's the greatest food of all time, it just sits in a nice spot on the taste/price/convenience/doesn't make you feel like shit when you eat it axis.