I'd agree with exclamation marks in prose, but surely if the dialogue needs it then you have to use it. I don't know how you can manage an entire novel with only one exclamation mark if you have several instances of characters shouting. To rewrite it so people never shout just to avoid using exclamation marks doesn't make sense to me.
You could use a tag or other means of conveying that they're shouting, so an exclamation mark wouldn't be strictly needed even though it would probably be the simpler approach.