The quality of being art has some positive correlation with being aesthetically pleasing, and has some negative correlation with being useful for practical purposes, but the determining factor is whether you can reasonably expect other people to consider it art too.

Intersubjective memes have a bootstrap problem (the concept is a supertype of "network effects"). To make something art, you have to make people believe other people believe its art. A way to brute-force this is to get someone to visibly spend large amount of money (or other resources) on it, and proclaim their belief in the value of the thing.

So it's not just the NFT "art" market that's being promoted here; the work itself is being turned into art, and the author into artist.