It depends on the intent of the author, for me. The generally accepted norm in comics is that the art is there to serve the story - which is mostly true, but for me, the two have to match. A fun, lighthearted story may be served with art which is very simple. (Not BAD, but simple.) A humorous or satirical comic can get away with art most people may call 'bad'.
But there are some stories which really need solid art to serve them, or it saps away some of the gravity of the story. I couldn't imagine the like of Full Metal Alchemist, for instance, with the art style of the average satirical webcomic. It just wouldn't work, and I wouldn't be able to 'fall into' it in the way I like to 'fall into' a good story. Immersion is important to me.
On the other hand, there are some artists - usually illustrators - who need only the simplest of narratives to pull together beautiful, lush pages in a compelling way.
Knowing what your audience needs to best engage with what you wish to create, and what your creation needs to best convey itself to that audience, is the key.