Complex writing equals intelligent thinking.
This grievous misperception is especially common to young writers, and I believe our universities are partly to blame. If you've ever spent much time reading academic papers, you'll know exactly what I mean. I doubt there's any genre of writing that contains more jargon, pretension and inscrutability.
And the people writing these papers are teaching our next generation of writers.
Back when I graduated as a freshly minted English major, it was completely normal for me to write in paragraph-long, multi-clause sentences. I was so smart I couldn't get out of my own way.
It was only after I got a job as a reporter that I learned to strip down my writing and stop using so many fancy words. And it was humiliating to discover that many of my ideas--once they sat there naked and uncloaked by jargon and pretension--just weren't all that impressive after all.
I think there's a lesson there. If someone writes in complex and incomprehensible language, what do you think they're hiding?