Because there is plenty of art that is not your jab, and you can certainly find value in anything and everything created--there's nothing wrong with that, is there? A nonexclusionary art--but some work, when analyzed, keeps speaking. You speak to it, it speaks back, and you keep on doing this--for hundreds of years, it never stops yielding.
You're complaining that people find meaning in things that you find meaningless, and that this means that the creator was merely bullshitting. No. False.
It's true that being good at art usually isn't so much a process you can write down into steps and that everyone could follow, as that it's a subtle, wordless dialogue with the universe in your own particular inner language. First there is practice, and then--inspiration, which cannot be controlled, which is unscientific to say the least. But the fact that the way to art is opaque, and that it is not objective, does not make it bad or bullshitted.
And no, I don't really like modern painting either, but on the other hand I am not so into pointillism or a billion other things. There ain't nothing wrong with Andy Warhol, it's just that his era needs to make way for something else and we're stuck in a perspective of oscillation between irony and sincerity, grunge and classical aesthetic, which in its dependence on hierarchy carves its own grave.
We're ready for a new movement, is what I'm saying, because the old isn't saying much on its own anymore. And, soon enough, we'll get one.