@tsarstepan,
Yes, accessibility is the answer. It's pretty, it touches the emotions, it's accessible and non-challenging. Impressionism in music is somewhat similar. When listening to Ravel or Debussy, you just have to lie back and let it wash over you. It tends to be programmatic describing scenes or feelings. It's fairly accessible, but still it's not my favorite type of music.
Impressionism in paintings is like dessert, everybody enjoys it, but maybe not as a main course, though one is tempted . It was an excellent transition from realism to modernism, which became less accessible and more challenging.