The reflexive "in mice" comments seem to be bemoaning how science is done.
The problem is not mice experiments on arxiv, the problem is posting those papers for broader dissemenation to the public, with titles suggesting to the public that cancer has been cured, without prominently pointing out that the experiments were not about cancer in humans.
Fair enough. I'm thinking of cases where a good study that isn't turned into PR slop is dismissed because it was done in mice. Which is fine for most people. But not great if we're treating real science that way.
This is science by ignoramus. It isn't how science works, at least not when it works at its best. Someone advocating for censoring science because it might be misread is not on the side of science.