Hmm. I'm sure that is not it, but likely the fact that the products are priced low enough that people do not leave feedback.
That said, flavor and taste are subjective. I find that MFS e-liquids are very good, where as someone like yourself may not like the same thing.
I actually purchased a 5 pack of pre-filled cartos as well from MFS, RY4 and 12mg. The person I bought them for absolutely thought they were way too strong! Upon trying to refill them I found that they are the older type with a hard tip and silicon type seal, making them more hassle to refill than they are worth.
I have been to their site to pick up orders on many occasions, and they seem very busy. They are nice people IMHO, and have some stellar SunDrop e-liquid. It really does taste like the soda. It is my second favorite and an all day vape for me. I don't tend to like tobacco flavors nearly as much as others, so take it for what it is worth.
I really hope that they aren't blocking these reviews, as that is what helps companies become better at satisfying the customers desires.
Hopefully a rep at MFS will answer you're question!