This is a valid argument, albeit a pointless one.

We use the term natural specifically to distinguish between the.. natural and artificial.

A term like that is necessary.

I think sometimes the distinction is made between natural and artificial (human made) as a way to sway an argument. In many of these cases, the reasoning is tenuous if we examine with an understanding that the difference is sometimes arbitrary.

If anything, we should be more careful with our use of language. For instance; 'naturally ocurring' vs. 'human made'.