I guess the meme is because Uniqlo is cheap as fuck there that one have to be so poor to not be able to afford it. But ironically in my country, it's quite a prestige brand because my currency is even weaker so it's actually quite expensive.
As always with the memes, I agree that it's largely an exaggeration. But I can assure you that it is definitely getting too expensive these days, and I'll think twice before buying from them.