@Pamela_Erb I try not to take these things too personally. After all, a master was once a novice. How else will you improve as a writer? Unless the review says "your book is sh*t" etc... And gives no definitive reason why. Then, of course, that is not okay. I think constructive criticism is really good and helpful.
When you are writing on your own, it's very very easy to overlook small mistakes. This is why editors and proofreaders exist. If your grammar/punctuation is already great, yes it can be a bit disheartening to see someone else point out a mistake. But, no one here means any malice and we are all trying to help each other become better writers.
I think honest reviews are very important. If someone makes a small spelling mistake, I try not to comment on it, but if it's happening more than a few times then I definitely will point it out.
1 small mistake isn't enough to put it in my review.
Consistent grammatical errors, spelling and punctuation make it hard for me to read, so if I see that often in a book, I will say something.