I agree with the value of dialogue in story development, however, one reason serial dialogue-heavy scenes should be carefully re-considered is because of pacing issues. Many new writers don't yet have a feel for story pacing and the need to neither bore the reader to death with detail nor fatigue the writer with unrelenting fast action.
Patches of dialogue tend to move the reader through the story at a very fast pace, which is why it's a good idea to have some action going on during the speaking parts--it adjusts the pace of the scene. Likewise, there are times when the writer may want the pace to speed up, so the balance of dialogue-action-description should be appropriately adjusted to that end.
Once we have a first draft in hand, we should take a look at every scene within the context of the surrounding scenes, specifically looking at pacing (an experienced writer has this in mind when constructing the scenes in the intitial draft). Several questions should be asked of each scene. Here are some (others may want to add to the list).
What is the purpose of the scene, not only in advancing the story, but in developing characterization, scene-specific and story-specific tone/mood, setting, pacing, etc.?
What is the pace of the previous and following scenes, and is it time to consider varying the pace of the current scene (specifically, is there is a story-related reason to either speed up or slow down the pace)?
Are we creating reader monotony by having an unvarying pace to our scenes? Are the scenes becoming cookie-cutter in terms of pacing?
Is the story being shown too much through the words of the characters rather than through their actions? This all depends on the genre, of course, but I like to recall high school locker room talk, where I had the distinct feeling the guys who bragged endlessly about their exploits were all talk and little action. I like to use this colloqualistic extrapolation to my writing in evaluation of a first draft. Are my characters all talk and little action, or the reverse, all action and little talk? There is no formula, and this does vary with the specific characters and the spcecific story, but I also like to rely on a little parenting experience, again extrapolated to my writing. My kids learn way more from what I do than from what I say. It is the example I set that has the largest impact on their behavior. The same can apply to characters in a story and their impact of the reader.
Are the dialogue scenes used to try to whiz some info-dumps by the reader? Back story can be sprinkled through a story in a way that it does double duty--informs the reader about past events, and serves as a tool of help control the pace of the various scenes. Description can also be used as a pacing tool.
Are the dialogue scenes that we think are adding depth to our characters really reducing that depth by giving the reader a numbing sense of "doesn't this character ever STFU?"
It will help to re-read some of your favorite stories with a specific eye as to how the writer controlled scene and story pacing, and how this was related to the balance of dialogue/action/description.