This is happening because governments have proven themselves untrustworthy when it comes to maintaining the “value” of fiat currency. They continue to print more and more of it. Why is it “not moral” to find something, anything, that can be expected to maintain or even appreciate in value and lock it away for the time when fiat currency collapses into valueless paper? The art will then be taken out and traded again for other commodities. It will again be visible to the public. But in the meantime there are countless copies the public can gaze on. As far as the original goes, we live in a world of private property. What is immoral about trying to maintain your financial status by keeping your private property safe and secure behind locked doors?
How many Picassos for a loaf of bread and a roll of toilet paper in Venezuela right now? I think art is a good holder of value against the continual grinding of inflation, but would be worthless in a hyperinflationary collapse. Also remember that gains in both art and gold are taxed as at a higher rate rather than capital gains so you get hit with high taxes for your attempt to fight inflation.