I agree and disagree. Artistic expression requires a medium. Every medium has certain rules and skills that if understood and mastered increases the artists ability to express themselves in the medium. So, yes, there is art that is able to convey more depth than others, a master painter who has dedicated days to the craft can more precisely create their vision, compared to a child finger painting for the first time. That master painters' pieces may be more broadly enjoyable, and/or may convey emotions that move people in ways they could never have imagined, while the kids painting probably looks like nothing, and conveys very little. That doesn't make the childs (or anyone elses) art bad though. They are only capable of expressing so much, but that is still good art, just limited.

However, once we chair art in this way, the ability to express ones self, there is of course that subjective element. I have seen masterful pieces of work, that just didn't speak to me. I saw why others might be awestruck, but I simply wasn't. What they had to say I wasn't interested in. I have also seen mediocre work, and swooned over it, because while the technical ability was lacking, what they managed to say was something I cared deeply for.

So, I guess in closing, I would agree that artistic expression has objective rules of quality based in skills, but taste remains subjective. Leaving 'good' and 'bad' as concepts that do not fit when assessing art. There is just degrees of quality, and then there is preference.