While your question is interesting as a psychological thought experiment, it does not matter pragmatically.
If I am interested in, say, sci-fi, or futurism, and so is person X - or, person X's marketing image - then person X will bolster their brand by posting sci-fi and futurism books.
Therefore, I still get recommendations in the genres I'm interested in, and whether those recommendations are accurate portrayals of person X's interests is irrelevant.
Comments
While your question is interesting as a psychological thought experiment, it does not matter pragmatically.
If I am interested in, say, sci-fi, or futurism, and so is person X - or, person X's marketing image - then person X will bolster their brand by posting sci-fi and futurism books.
Therefore, I still get recommendations in the genres I'm interested in, and whether those recommendations are accurate portrayals of person X's interests is irrelevant.