With all due respect, "fans" is a vague term, where Barbie is concerned. What kind of "fans" are we talking about: the older fans who think less of her now then they once did (i.e., who see Barbie as nothing more than just a toy), or the fans (age regardless) who actually understand who and what Barbie is really all about and who focus on the message both the character and franchise are really trying to give (i.e., "be yourself", "anything is possible", "you can be anything you want to be", etc), and who even not only put that message to good use, but still actually like Barbie for who and what the character and franchise really are? For these reasons among others, my previous point about the movie possibly being another tribute/parody movie still stands ("anti-fans" or not). That said, I can only hope that it will be an actual Barbie movie that's actually about Barbie...
The American dictionary defines a fan as an enthusiastic devotee, follower or admirer of a sport, pastime, celebrity, etc. One's personal interpretation of fandom is irrelevant. Regardless of how one chooses to define fandom in this particular context, the fact is that Barbie has plenty of fans. the fact that the toy line and the franchise have endured for nearly half a century should be proof of that. I would think that the main people who think of Barbie as being "nothing more than a toy" are the executives who only know profits, sales and shares. However, the movie is being made by executives, not for executives. Executives who neither know nor care what sort of Barbie fans are going to see the movie. It only matters is said fans have cash and are willing to pay 10 + dollars to go see Barbie on the big screen.
The "tribute/parody" movie that you keep mentioning isn't a thing. There have been, maybe 2 movies like that made in the last 20 years, so it's not a genre onto itself, and with all due respect, your belief that every kids' movie is going to turn out this way is just a tad paranoid and unfounded. If your interpretation of a movie that can be enjoyed by both children and adults in equal measure is "parent service" (which isn't even a thing, btw. You made that up), then naturally, you're going to assume that any and every movie that succeeds on more than one level is being made for "anti-fans". Using your logic, Marvel's The Avengers was a "movie aimed at adults at the rest of the family's expense" because it was enjoyed equally by adults and by children. But here's the thing: fans don't have to prove to you, me or anyone else that they are fans. Anyone who considers themselves to be a Barbie fan is going to go see this movie, and anyone who doesn't consider his/herself to be a Barbie fan isn't going to bother with it. That's the long and the short of it. Whether or not these movie goers meet one's personal standards on what a fan is or should be is irrelevant, as previously stated. It should only matter if these movie goers pay to see the movie in theaters, which is how box office success is defined.
Am I saying that I think the Barbie movie will be perfect? No. But I at least believe that Mattel has some idea what to do with this project. seeing as how the company has has several successful doll lines and has produced home videos which seem to be selling (they keep making them, someone must be buying them!) and a web series which is currently in it's 4th season (I believe), so I'm cautiously optimistic that it will turn out well as opposed to merely assuming that any and every kids project is going to turn out badly before learning anything about it. Given that, there's no reason for someone like you to go see or even learn any more about the movie, since you've already convinced yourself that it's going to be bad and that said movie doesn't meet your (very) specific standards of what a kids' movie should be.