I think this is true, but for far less malicious reasons. Favourable reviews lead to popularity, which increases production pressures, which makes it harder to source quality materials and maintain a quality process while satisfying demand.

I have heard of several indie makers who, faced with sudden popularity, have to make the tough choice of speeding up the process at reduced quality (and thus dissatisfy customers) or be unable to fill orders (and thus dissatisfy customers). Everyone handles it differently but it's not pleasant for anyone.