Tip #73 from our Writing Tips for a Year addresses the issue of sentence length and simplicity. I have copied it here.

“I notice that you use plain, simple language, short words and brief sentences. That is the way to write English—it is the modern way and the best way.” – Mark Twain

I was once asked whether our editing strategies are appropriate for creative writing or if they are only appropriate for business writing and other formal writing contexts. The answer, of course, is “Yes, they are appropriate for creative writing.” Many of our editing strategies echo Mark Twain’s comment above, and few people would doubt his ability to write good fiction.

When you are imparting information, whether in a technical document or a narrative document (such as a fiction novel), you need to consider how to impart that information effectively. Styles are different, as are the readers, but writing simply and clearly is necessary to accomplish the purpose for which you are writing.

I did some translation work a couple of years back where the original copy was written in huge sentences which were often over 120 words long! The writing was being done by a young lady who had no training in writing. It was a nightmare.

I favor longer sentences. Shorter sentences make me seem amateurish (which I am ). However, longer sentences increase the number of commas in my works, and I’m tired of that. Pretty sure readers would be sick of them as well.