My argument was always that classical artists always seemed to be looking for new methods to improve their work; usually citing Da Vinci's use of new materials, techniques, etc.

In fairness, this is like saying, "Modern science is shit, because Newton and Darwin accomplished way more than anyone alive today." Sure, the second part of that statement is factually correct, but it's also a non-sequitur. The filter of generations has been applied, and geniuses happen only ever so often. We're not geniuses, you and I and most people doing art. That doesn't mean there aren't some cool artists out there doing rad shit.

Can't link to their website at work, because of my stupid firewall, but check out the Outsider Art Fair in NYC (or hell, go if you live anywhere within a few hours), as an example. Tons of awesome and stupid shit there, and everything in between.

I think some problems arise from context. If you go to a gallery or an exhibition of a modern artist whose appeal isn't obvious, it could be that it's because the work has been totally decontextualized and stripped of meaning that the artist probably wanted it to convey. In my experience, talking to artists about their work usually makes things way more appealing. This isn't really possible with most art, obviously, but it's totally possible at fairs, art openings, etc. Most people who create are all the happier talking about their creation, because it means someone actually cares.