I plan to write more opinion pieces in the future, and I promise to make it flow better. Keep in mind that the current text was initially a part of my Captain America: Civil War review. After I saw it grow, I decided to dedicate a separate space to it... So without further ado, here it goes:
I consider myself a hardcore fan of DC comics. There was a time that I used to read 4-5 comics every week; now I read maybe four per month... So I cannot objectively compare Batman v Superman with Civil War. DC characters mean a lot more to me as a fan. Seeing the Trinity of Batman, Superman, and Wonder Woman on the screen literally gave me goose bumps... Obviously I did not feel such excitement when I watched the Civil War.
I have a beef to pick with rottentomatoes.com ; their ratings build false expectations for the viewers. They gave BvS a 28% rating, while Civil War got 91%. Maybe one of the reasons that I didn't enjoy Civil War that much was the ridiculously high expectation that RottenTomatoes had built for me.
A simple definition of satisfaction is when one's experience was better/greater than the expectation. My enjoyment of Civil War was definitely not on par with the 91% rating, thus I left the movie theatre unsatisfied.
RottenTomatoes uses a binary system for aggregating reviews; if it was a favourable review (e.g., 3/5), they code it as 100. If the review was a little less favourable (e.g., 2/5), it would be coded 0. This coding scheme is polarizing and surely has a high variation in the result.
Instead, I recommend MetaCritic. Instead of binary coding, they simply convert the review score to a percentage (e.g., 2.5 stars out of 4 is 62.5%). They also use multipliers (or weights) to reflect the importance of some reviews (e.g., Richard Roeper's reviews are given more weight than some unknown reviewers'). Their approach is statistically sound (relatively), and perhaps gives a more accurate impression of the critical reception.
At the end of the day, reviews, statistics, and statistics do not matter. Maybe it's best to experience a movie/tv show/video game first hand, and then read others' impressions for additional insight... Just my two cents.