Personally, the abstract modernist line of art really doesn't do anything for me or the "rocks" or other "shock" art. But I think a lot of this art comes from continuing to push into new creative territories. Imagine if you were an artist and all you could do was use the same style as everyone else had for the last 2000 years? We had a whole discussion about this a couple of weeks ago. I used to enjoy amateur photography for several years, but then google images came out and I realized I could find virtually any picture I ever wanted to take had already been taken by someone with a lot more time and experience. So for me I just didn't bother anymore and moved on, but real artists don't do that. And this same kind of thing happens with writing, visual arts, music, literature, etc. Art must continue to change or it just gets boring, for the artist and the admirer. Plus, almost all the famous artists who created new forms of art were disliked in the beginning.
And don't be misled by the "professors" suggestions that the impressionists were somehow an "objectively" aesthetic and accepted group. They were completely rejected by the established art scene when they first started their work. Their work was seen as lazy, imprecise, and just plain terrible too. Now they command some of the highest prices for any art in the world. And in terms of some modernist art, "aesthetically pleasing" is not the point and it requires a learned understanding of its purpose, historical place, context, etc in order to "get it." And to suggest that Jackson Pollock was some kind of simpleton who lacked a philosophical foundation is an insult. He was continuing on the line of creative artistic development that had come before him, but also trying to add his own self to it so to speak.
In the end though, I do enjoy classical works more though :) Maybe that's just because they are "easy" to enjoy, but who is going to tell me that I can't enjoy them? (I do however enjoy "difficult" works of art in other areas of the arts, so there isn't any consistency for me either)