What exact ethical issues are there? Article does not mention any.

Indeed, there's much more going on in biological systems than just merely a replication. There's both anabolic and catabolic reactions, and compartmentalization allowing for these reactions in the first place. There are different receptors acting as an input signals that influence the aforementioned reactions. Viruses lack all of that, including arguably even replication, which they can't do by their own. There's not even any spectrum here - viruses don't have any biochemistry, and even the simplest bacteria or archea exhibit all of the processes mentioned.

Virus is a handful of molecules that in a certain environment tend to react physico-chemically as the chemical structure and properties of molecules dictate. If you deem it as an "active and deliberate" you'd have to consider every chemical reaction as active and deliberate. By this definition, a catalytic converter in your car is alive.

But viruses cannot replicate unless they're inside the cell. But you can say the same about just the nucleic acids. They cannot replicate - they're just a chemical molecules. Unless they're surrounded by a particular molecular machinery that allows them to replicate. By your definition RNA and DNA are alive.

You seem to skim on the fact that living things also metabolize and viruses don't. Also - constant change in response to the environment can also happen in non-living things, eg. rivers.