Tolkien’s legendarium isn’t a “franchise”, brigading is the work of trolls not fans, and the degree to which it panders to an existing audience is the most tawdry, and least interesting, measure of any creative work.
Emotionally invested fans of these stories clearly exist and describing them as the core audience isn’t a dishonest claim. Neither is it dishonest to claim that some of these fans feel alienated by the new versions of these stories.
You can debate both claims, and my views don’t align perfectly with OP’s either but there is no intellectually dishonesty on the the part of the OP in making the claims.