I do many artistic things that are banal, transitory, and meant just for me.
Some are as simple as dishing up dinner, taking a picture of my wife, or building a sand castle. Where "I" am the whole audience, no other opinions matter.
I know some people might suggest that that dishing up dinner isn't art.
I'd also bet that any great chef would give you an earful if you disparaged the art of meal presentation as simply throwing food on the plate.
What can't happen in a vacuum is earning a living off art.
It is only when we expect to profit from our art and fit into "the market" that external opinions begins to matter.
It could be easily argued that personal art, made in a vacuum, is actually more pure, special, and important.
If that personal work happens to find a market, that's just gravy.