A teacher once told me, "Show don't tell, except when telling is better."
I notice, in my own reading, that I generally want to skip over the telling parts of a story--the long beautiful lyrical descriptions, the internal musings, etc--so I can get to the scenes where stuff is happening. So, when the author is telling-not-showing I've skipped that information.
I usually write about broody dopes who think about stuff too much, and as I externalize thosethe characters' thoughts in revision the story improves. Even if the externalization is as simple as a dialogue (frequently interrupted by physical actions and interruptions to keep things going).