What kind of art do people like? Banksy vs. Plein Air
Studies have been done on what people like in art. It turns out that most people like blue, people, animals and landscapes.
blue, people, animals, landscapes

art that doesn't offend
Art that blends
I might add that most people tend towards familiarity in their art or at least art that's easy on the eyes or doesn’t offend. Most prefer middle of the road art to hang on their walls. It’s what they want to see over and over again. 

da Vinci anatomy

And frankly, I agree, to a certain extent.
I really don’t want to look at skulls, death, aggression and political commentary on my walls on a daily basis. That would personally be too much of a subconscious downer for me. Although I could make an exception if it was an anatomy drawing by da Vinci but probably not a Warhol skull.

But going off mainstream and
fringe can propel art forward

being on the fringe is what can propel art forward even though it’s not the most popular. 
Fringe is a documentation of the mindset of the people at that time. It’s history in the making. Many museums prefer fringe art and it’s what many serious collectors seem to go for. It’s exciting to be a part of history and on the cutting edge. It’s the idea of new and different. And, in some cases, gambling that it’ll increase in value. 

Duchamps "Fountain"
Fringe is a documentation  
of change.
In some cases it’s
attempting to make the mind grow and in other cases not so much. Fringe, like Duchamps “Fountain” or Banksy “Parachuting Rat”, attempts to
change the course in art but for most people it seems a good plein air landscape is the best.

warehouse from
Raiders of the Lost Arc
I wonder....
If Duchamps' "Fountain" came up for auction, would the buyer display it in their house? I have a feeling it would end up in a vault somewhere. But for now it's probably in a warehouse for safe keeping.