Honestly? The only thing undertale was a victim to was people who couldn’t mind their own damn business, who pulled weird au’s and sexy sans and whatever else out of their niches on a into a spotlight so everyone could laugh and ridicule it until it became a meme, and once it was a meme everyone got sick of it, leaving the “fandom” to blame for undertale becoming associated with the jokes they didn’t make in the first place
Where I come from, we call people like that “bullies” but (shrug emoji)