I think most of that anti-Kmart stuff had to do with it being the 80/90s. $150 Polo shirts are nowhere near as popular as they are now, in fact compared to my preppy ass most kids look...homeless, pretty much, nowadays, so I doubt there is as much fashion shaming.
For anything but clothes, tools, bikes, and electronics though I don't really get the Kmart stigma. I got most of my Transformers and King Vitamin and whatnot from them and they come from the same factory as the ones they sold at Hudsons so it's a pretty stupid line of thought, IMO.