On a G2 Review Tools call with Katlin Hess she mentioned that people often freak out when they receive 3 star reviews.
She also mentioned that in a study the 3 star review is the most trustworthy.
While this might not make you feel better about a 3 star review, it is nice to know that customers value them and they sound necessary.
This is another reason why we shouldn't only focus on positive reviews but we should open reviews for all customers to submit.