Primark profits on the way up, by a recession beating 16% but... many charity shops refuse to take items from Primark because the quality of the garments isn't high enough.
Is cheap nasty?
Well no, but if poorly made clothes, that only get worn once or twice are you thing then there is a place.
Is fast shopping as bad for you as fast food? The occasional cheap shop like fast food won't do you any harm but if you only eat burgers and that becomes your diet then you will have some serious health issues.
There are those that invest time and money to establish their brand, then there are those that, simply copy.
The same applies to most services and products, long live originators and innovators.