They never said that viruses are alive, so I have no idea why you even mention it. And it doesn't matter anyway, unless you can show me an objective universal definition of that word which at least a majority of relevant researchers can agree on.

Being alive and having a "reason" is not the same. A complex but definitely not alive machine like a car has a purpose and does it's functions for a reason. Ultimately, all things do what they do for a "reason", be it just the laws of physics.

If instead you meant "reason" in its second meaning, based on consciousness, then it fails just as well. Bacteria are considered alive by almost everyone, yet they have no mind to speak of. They don't reason with themselves at all, they just do like a bio-machine.

If you think that it matters if viruses or prions are "alive", then you are wrong. It simply does not matter, what counts is what they do (with or without "reason"), and that is exactly what the post your responded to described. No researcher would suddenly change their approach for treating or preventing rabies or covid if you or anyone else decides they are (not) alive.