I think the conclusion is self-evident to any avid reader of literature. I can't think of a single good author who abuses exclamation marks. And that's because someone who abuses exclamation marks in this way is a pretty poor writer by definition.
Or, less snarkily, I don't think it's self-evident that a writer who uses exclamation marks a lot is a bad writer (although I can't think of a counterexample). What leads you to say that?
(also I'd argue that "abusing" exclamation marks follows from your judgement of "bad writer". Any good writers would be using exclamation marks, not abusing them)
