Joe - the problem isn't the scene enhancing musical themes, it's the unhelpful stuff which just swamps the scene to the detriment of the story.
Music can add to a drama or comedy, but only of it is appropriate to the scene - run the Keystone Cops style chase music when a funeral procession passes and you no longer have sombre drama. On the other hand, when done correctly, it enhances classic movies such as The Big Country with grandiose music across sweeping scenery, or The Magnificent Seven, where snippets of the theme tune hint at what is to come, but do not turn into the main theme until the final member joins.
My complaint isn't when it is done well. If done well, for effect, you may think "Oh wow! That's Good", and if done for subtlety, it enhances the scene, but it is appropriate, so it doesn't distract from what is happening. It may set the mood for a romantic interlude, wring tears out of you when the sick character is finally fading, or focus your attention on the fact that a giant shark happens to be getting closer to the boat, but whatever it is, it belongs in the scene.
Our complaint is that increasingly, it is at best irrelevant, at worst downright intrusive and in either case spoils the scene.
Quack!
Geoff the (background noise of distant flock of wildfowl) Duck!