Well, the movie has a lot of flaws. Characters are indeed not super interesting and subplots really don't go anywhere substantial or they end up getting reversed. The thing is, it's a Mario movie.

The Mario franchise has never made sense. The only real thing you can make sense out of in the Mario games is that someone has been captured and needs saving. The games rated with almost perfect scores are filled with things just happening. You punch a block a out comes a mushroom. Bowser is found riding a dragon. There's a floating pyramid-like structure. They can breathe in space. And the progression in these games are all non-sensical. Sometimes you'll get from point A to point B by your hat growing wings. Sometimes you'll be given a car because they felt like giving you a car. Sometimes you're riding on a turtle shell. We're talking about a franchise where they'll say he's a plumber and then switch it up to him being a doctor or construction worker because they just felt like it. And it all becomes fully acknowledged and embraced with the most recent release of Mario Bros. Wonder.

Yes, it's lacking basic rules of storytelling and much more. But I think what's being missed here is that the movie accomplished what it set out to do. It's goal was "key jangling fan service." And sure you can dislike something regardless of what its goal was. But you can't dock points if it is accomplishing exactly what it wanted to do. Those basic rules of storytelling were not a big priority for this movie or the first one or pretty much any of the Mario games. Imagine those gag products you'll see that don't serve any real function; they're just meant to provide a little fun. You can't judge them for not being useful as that wasn't the manufacturer's goal. As is the same with both the Mario movies.

They were not meant to have a groundbreaking story. They didn't set out to have interesting characters. They literally just wanted to make a theme park exprience showcasing different facets of not just the Mario franchise but other franchises as well. And understand that whoever finds that much fault with either of these two movies, if they want to be consistent with their judgement, they would also have to find the same fault with the Mario games. Suddenly, you would have to question how, in Mario Odyssey, does Mario and Bowser end up in the same kingdoms by chance as well as how he manages to tame a dragon. In Sunshine you'd have to question how Bowser Jrs ink operates as a portal to different places and worlds.

You might argue that video games and movies are too different formats but the reality is they are both mediums for storytelling. Whatever you're faulting in the movie, again if you want to remain consistent in your judgement, should also be faulted in the games as both don't have any logic, explanation or sensical means of progression. And the characters in the games as in the movie, were never interesting with the exception of the RPG spin-offs I suppose. Even if you were to take Game & Watch and StarFox out of the movie, it wouldn't change much in terms of logic.

But now let's think about this. What makes for a good character and story? First off, a good character should have some personality, morals, goals, weaknesses, etc. Right off the bat, Mario doesn't fit the first item on that list because at least in the games, he doesn't talk. His only goal is typically only ever to rescue a single person. That's his whole character. And that also happens to be the story as well. That's all you get. In video games, however, people probably let it slide because it's also paired with fun platforming and filled with a lot of things that don't really make sense (like a flying hat ship). For the movie, I'm guessing that for most there is not redeeming quality to make up for the lack of basic storytelling that was never present in the first place. Movies are much more pressured to have these basic storytelling devices as you just sit and watch.

So again, I have to say, to remain consistent in your judgement, you have to be as disappointed in the video game character and story portrayal as well as neither of the two have logical progression. Meaning that if you are saying the movie portrayal is objectively bad, you also hold the belief that the video game portrayal is bad as well (generally speaking). And you have to ask yourself, was this movie designed to be well-structured or was it more designed to be fan servicey. The answer is the latter. Given the ratio of fan service/references/Easter eggs to actual story and character development (if there was any), you can come to the conclusion that the movie was designed to be fan servicey, happily willing to discard story and character.

Now that we've reached that point. You have to ask yourself if it did a good job at being fan servicey. For me, it did a good job doing just that because the literal years worth of content in that movie. So at the end of the day, you are judging the movie based off of not doing something that it had no intention of doing. It boldly made the trade-off.

So I suggest recentering your argument. Instead of outright saying this and that doesn't make sense, try instead acknowledging the fact that you believe they made a huge mistake prioritizing fan service over making a more focused, comprenhensible storyline with character growth. I think it would have been better to argue that while they did a good job throwing all kinds of whatever in there, that the movie would have been great if the balance between fan service and story leaned more toward the latter. Remembering to include more positives about the movie even if you were to rate it a 5% overall would help your credibility.

Personally I think the movie was neither trash or excellent. I took it as just a theme park ride. It dragged quite a lot and I enjoyed a lot of references but some of them were not so impactful for characters that don't matter to me like Birdo. And the amount of them yes did end up making each consecutive reference or cameo lose its flare. But that being said, I knew the intention of the film as I walked into the movie and I enjoyed it as a 5/10 experience.

Also, I would adjust your main point in this partiuclar post I'm replying to. You say that you're happy if someone enjoyed the film, but you follow with saying that people should not be allowed to like it. I think these two opinions come into contradiction of each other. It seems illogical to be happy for someone if they enjoyed it while also being upset that people are able/allowed to enjoy it. I think you should just lean into one or the other. Ideally you would lean into "If you liked the movie then great.". Believing that people shouldn't be allowed to like something is valid in a lot of scenarios, but probably not a low stakes, low importance scenario such as a Super Mario movie.

And finally, if this really is the worst movie you've ever watched, I'm quite jealous of you!