If it's not a scream, don't use it
While I'm mentioning pet peeves, I may as well get this out of my system.
An exclamation point (!) turns an entire sentence into a scream. Using this punctuation after one to five words can be appropriate. It's particularly applicable if it's used with a quotation of someone who has lost an arm or leg within the last few minutes. Using it after a long list of proper nouns is forbidden.
The rule of thumb is to stand and shout the profoundly punctuated sentence. If the author's air supply expires prior to the end of the sentence, delete the punctuation and use a period.
Before I started journalism, I was as guilty as the next person of using it to express emotion or importance. To be fair, people have gotten more computer savvy and use fewer exclamation points. This is good.
The original problem may have been typewriters. There was no easy way to write bigger or bolder. The only options were to underline the sentence, change to a red ribbon or type the same letters again and again over each other until the words became darker. So, the exclamation point was used (incorrectly) as shorthand for bold or italic fonts.
I disliked my first (mechanical) typewriter for this reason. There were many reasons I disliked my first typewriter, but I'll save those thoughts.
However, I loved my daisy-wheel typewriter. I remember how quiet it was and the letters could be erased (see, I restrained myself from using the exclamation point). It actually remembered an entire line of text. How amazing! <-- This one is OK by the rules set forward.
I need to write about my typewriter one day. It was so cool.
Enough for now,