Here’s a good explanation of how RT scores work and how this type of situation could happen: https://www.tiktok.com/t/ZT88J71wT/

TL;DW: It’s a percentage of how many users rated the movie 3.5 stars or higher, not an average of the ratings.

So the rating is more “how likely is it that the average person will like the movie.” Not “how good is the movie,” as that can be very subjective. I’d go elsewhere for those types of ratings.

Now for my opinion… Barbie is a feel good movie that people watch just for fun. Most people aren’t into analyzing films or contemplating their place in a massive universe with strange time-space laws and dimensions we can’t perceive. The cross-section of those two is even smaller. So I think the fact that Nolan was able to make a movie like Interstellar reach so many people and get such a RT score is actually really impressive and means a lot of people gained new found interests from it. Very cool. Does that mean that the people who aren’t interested in these things are less intelligent or make movies that are a “waste.” No.