Although, I don’t advocate that you just always buy Wirecutter’s recommendation because you might value some attributes higher than their reviewers do. But when I’m looking to make a purchase, I typically start by looking at Wirecutter. I then weigh the different options — they typically have a main pick, a budget pick, and an upgrade pick — then I look into the reasoning behind each recommendation, look at pricing, aesthetics, and choose which one is best for me.
This is good advice, and applies very much to how I treat things like Rotten Tomatoes. These are great places to start looking for things to buy or watch, but they are certainly not the last word on anything for everyone.
You don't need to buy the Wirecutter recommendation every time, and you don't have to only watch the highest rated movies on Rotten Tomatoes. Also, something scoring great or terribly on one of these sites does not "prove" it's great or terrible either.