It's because they've drawn a conclusion already:
That there has to be other intelligent life elsewhere in the universe, and (in many cases) there could not possibly be a God. Finding mold on a rock outside our gravity would a smoking gun to prove it. Therefore any evidence that could be used to argue in favor of that theory shall be trumpeted from the mountaintops, and any information that diminishes it will not be factored.
If my pointing out the stupidity of saying,
illustrates ignorance on my part, believing such a statement certainly illustrates profound naivete.
I do not take issue with that statement because I have a problem with the concept of other worlds inhabited with highly intelligent peoples or because such believes compromise my belief in God. My problem is "scientists" and other "educated" elites making insipid statements, and millions of people accepting them as fact. Just like the MMGW hoax, only more so because there are so many scientists that dispute these theories, but are ridiculed by the "educated" elites in the leftwing fringe of both the scientific community and the media.
If I were God, I'd have planets all over the universe teeming with life. He probably likes watching wars, and eventually we'll be involved in intergalactic battles. In any case, in His infinite wisdom, he seems to have spaced the planets so far apart the rest of the universe is safe from liberalism.
You seem to be drawing a conclusion ahead of time as well, although you are not too far off for some of my fellows. However, before you assume all scientists are from Berkeley, remember many are highly positive about live existing on other planets because they want it to be true, which is because they are NERDS, and want scifi to become reality.