Just want to point to one of my favorite over-modified phrases, just to show I'm not a fuddy-duddy:
...the deep South dead since 1865 and peopled with garrulous outraged baffled ghosts...
That's Faulkner -- Absalom, Absalom. I have always loved that "garrulous outraged baffled ghosts," and loved how he did it without commas to create that propulsive effect.
Why is that okay and "towering high mountains" isn't?
1) It's not redundant. None of those adjectives are synonyms, and none of them are obvious connections to "ghosts".
2) Each modifier adds something new and surprising. Garrulous ghosts? Outraged ghosts? Baffled ghosts? Those are some cool ghosts.
3) "Ghosts" itself is a modifier, or at least a descriptor, a metaphor (the people in the south aren't actually dead) for the lost and angry white Southerners who just couldn't believe they could lose the war, or especially that they SHOULD lose the war.
4) The modifiers are interesting words, and well-chosen (though when I recite it, I often reverse the last two because the rhythm sounds better to me). None of them clearly lead to each other, but together they resonate-- garrulous but baffled, and of course they'd be outraged if they are garrulous (expressive, loud) and baffled, and especially if they find themselves to be ghosts.
5) The phrase expresses something interesting, something meaningful. There's no triteness there in that phrase, no slackness. It's taut and thoughtful; it expresses the anguish and fury that powered the vicious actions of the post-war century.
6) It sounds good. I'm not sure why. I like the garrulous/ghosts alliteration. Also there are several a-sounds, but notice each is a different a-- gAHr, rAYged, bAAff. And several O sounds, also each different -US, OU, OH. I think it has all those sound links, but also profoundly different sounds, hard-g and fricative f and the plosive B. I'm a sound slut. If it sounds good, I don't care about sense or meaning or depth.
But there is meaning and sense and depth. This is over-modified with purpose, as so many of Faulkner's great sentences are-- piling on the power and the meaning with each word. Can't you just hear one of those ghosts? "I'm garrulous! And I'm outraged! And I'm baffled, goddamnit!"
That's voice. That's taut and meaningful and reflective of the situation. The over-modification forces an accumulation of emotion and theme that adds great depth.
You have control over your sentences. You can make meaning by combining words. And you can break the rules whenever you like-- as long as it adds to the meaning-- and the reader gets it. (So often, frankly, writers say, "Oh, I did that comma splice or sentence fragment to convey XYZ," but if the reader doesn't immediately get it or feel it, you haven't done it right.)
I just love that. Garrulous outraged baffled ghosts. They're still there. I was just in Richmond (my family is there), and those ghosts are roaming Monument Ave., still grumbling because Arthur Ashe was given a monument on the boulevard of Confederate generals. I just hope Arthur is a triumphant happy serene ghost. :)