I got criticized once that my writing style uses simpler words. Why not show off your vocabularly or use more sophisticated verbage, they asked. My answer: I'm writing for a wide age group, and vocabulary is only useful if it adds to understanding, not if it takes away from it.
For example, my friend, a talented writer, just tweeted this from his WIP: "Her soul was gnawed through, suffocating, sensitive though numb." Out of context, that does very little for me. Intriguing use of words? Yes. But meaningless without more context. Knowing this friend, he'll give it the context. So I'm not worried about him, but I've seen plenty of writers who use words like this and end up with a jumbled mess.
Have you ever been reading and come across a word you had no idea the meaning of and it ripped you right out of the story and world? Do you hate that? I know I do.
Publisher Candlemark and Gleam offers this comment: There’s a difference between having a good vocabulary and a good grasp of wordplay and being overly clever; think of the poor, overused thesaurus before running amok. Trust us, saying “her violet orbs welled up with viscous, salty fluids” does not, in fact, work as well as “her eyes brimmed with tears.” Won’t someone think of the thesaurii?
It's not that I'm not impressed with a good vocabulary. Well used, it can be both educational and intriguing. I often go through during polishing and substitute words using a thesaurus. This is to keep it from being stagnant with overly repeated words. But I'm very careful where and what I replace. It does you no good to show off words when the reader has to look them up constantly and step out of your story. It's distracting, annoying, and, in the end, insulting. Writing is communication. Communicate with your readers. Fiction is story telling. Telling them a story doesn't work if they don't understand it.
So when I've heard people criticize my lack of sophisticated words on occasion, I point to authors who are quite successful and don't need that. Authors like Mike Resnick, Orson Scott Card, Kevin J. Anderson, Timothy Zahn, to name a few. I'd much rather have words a lot more people can read than words only suitable for a select few. How about you?
Part of having a vocabularly is knowing when and how to use the words. If you can't do it well, you don't really own those words. So don't try and fake it, because, trust me, readers will know. And it won't give you cred. It will take away cred.
For what it's worth...