I think it's very important to make words count, but it also depends on what you're writing and who your audience is.
For example, I write a lot of poetry. One of the styles I write frequently is haiku. I love the challenge of creating an image and trying to get it into 17 syllables. It's difficult, but not impossible. I like to write free verse poetry as well, but when I can't condense the image, I find that I often go back and revise it into a shorter poem later.
I also love writing longer fiction. You can't always make things as concise as possible, especially if you're writing original fiction in a setting nobody has seen before, such as science fiction or fantasy. In that situation, descriptions are necessary to build images.
In fan fiction, writers tend to not be as descriptive because they're writing for an audience who also happen to be fans of that TV show, comic book, movie, etc. and know what the characters and the settings look like. The descriptions tend to focus on the characters' actions and dialouges, rather than other things.
But that's just what I've noticed since I've been writing.
