That's not what's happened. There have been some other promising results, and some ambiguous results, alongside that one fake.
If LK-99 really is a superconductor then there's nothing that the negative-nellies are ultimately going to be able to do about that. When trains are levitating around on superconductive support, when every corner clinic has an MRI machine stashed away in a back room, are they going to just continue confidently declaring it's all fake? Sounds like a fun way to live. That's not skepticism, that's insanity.
Preemptively declaring LK-99's superconductivity to be impossible before it's been thoroughly vetted is just getting a head start on that.