Looking at art from the perspective of a century after it was introduced and its effects have become incorporated into mainstream culture just not that useful.
I find the best museums and exhibits help you get into this mindset; I'm reminded of an exhibit I saw at the Tate Modern about Picasso in 1932. It provided not only the context to his art, but to him as a person. I was able to better understand how his art was shifting at the time due to the nature of the world around him and his personal relationships. It really allowed me to see the artist through the art and the art in its context. https://www.tate.org.uk/whats-on/tate-modern/exhibition/ey-e...
I hope that I can take this idea to domains outside of art as well; considering the context of everything we encounter is important for a better understanding of our shared world.
I mean, I can look at art created thousands of years before "Fountain" and appreciate it, but still consider Fountain snobbery, can't I?
For centuries artists have tried their best to create the most beautiful artworks possible. This lead to an association of beauty with art. Art must be beautiful. You challenge this idea by making something that is not beautiful but people will still consider as art.
Otherwise, if everything is art as long as someone tells me it must be so, the concept of "art" becomes meaningless to me.