It's the "panspermia angle" that's "rejected by the scientific community at large", whereas the other findings (i.e. lack of DNA) are "yet to be verified". One step at a time: they may not be able to show extraterrestrial origin, but they have experimental evidence of reproduction at high heat, and an apparent lack of genetic material. If nothing else, those points are _extremely_ interesting.
I guess the question is, why does this theory deserve to not be dismissed? There are (pulling a number out of my ass) tens of thousands of theories on anything and certainly not enough resources to test them all. I think the burden of proof rests with those pushing a new idea. There are people working on this, but without further substantiation, there's nothing special about it.