Well said. I agree with many of your points, especially in regards to the studio marketing push to equate Rotten Tomatoes with a solid "grade" the film receives. The site itself (or at least their social media) is also to blame for this as they often have little digital "countdowns" to the revelation of a film's Tomatometer score.
I'm also in the camp of removing myself from applying numerical ratings to movies these days. Meaningless labels like "10/10" or "6/10" reduce films down to a certain set of standards and qualities that people believe can be applied to arbitrary numbers. There is no such thing as a "perfect film" to me (or at least, not enough to make it a prominent phrase in my vocabulary) so a film given a perfect rating seems more disingenuous to me than helpful. Likewise for a film with a middling rating like 5/10. What does that even mean? The film is 50% good, 50% bad? It's nonsense.
As a film major, I find myself agreeing with critics more often than not because I believe most of them come from a similar academic background as me so I can understand what they would see in a film and how it succeeds/fails at that. The typical audience member normally goes into a film with a one-track mind solely focused on being entertained and while there's nothing wrong at all with that, it's not exclusively what I see movies for. That's why the Audience Score for me on RT is an utterly pointless widget. Scores generally range from the 80-90% mark for almost any film and at that point if everything is loved by 90% of the population, why bother listening to it?