I was wondering if someone could tell me the natural way of saying "I don't think X". The reason is I wrote the following sentence:
普通の食品店で売っていると思いません。
I don't think it's sold at the normal grocery store
However this was corrected to:
普通のスーパーでは売ってないと思うよ。
For the most part I think I understand the corrections. But what I cannot understand is why 売っていると思いません was changed to 売ってないと思う. I don't really see a difference here outside of emphasis / focus. To me 売っていると思いません reads as "I don't think it's sold" and 売ってないと思う reads as "I think it's not sold" in English. And in the end, they ultimately have the same meaning to me.
So was this actually needed / a valid correction? Is it more natural to say negative statementと思う in this case? I have never been corrected using ○○と思いません before and have used it quite often.