It really depends on who's writing, what the story's about, and the characters. I had to write a short story for English class. It wasn't anything fancy. I just wrote about a princess in a technologically advanced world who wanted to excape her castle to get out of marrying an evil prince. We had to edit others stories and were put into groups. There was one part where the princess was talking to her elderly nursemaid and I mentioned her face. Get this. One girl that edited mine actually suggested I change the word face to visage. Trust me, the character would not talk like that. There is nobody in the books world(Imay expand on it and write books) who talks like that. The only reason the word exists is to make you sound smart, and none of the characters need to sound like that. I just laughed because the suggestion was idiotic. I know my story and characters better then anybody else would and I know a word like that doesn't fit in that kind of context. I read her story and it was full of those words that really didn't add depth to her story, but maybe that's how her character thinks. I don't know. The point is that big words should only be used if it's appropriate. It doesn't just make writing look bad but it makes it look like it was forced. Anybody knows it's not good to force things. You just have to let things go. So really, it all depends. If the character your writing about has that kind of vocabulary, then write their thougts and feelings. So it's not like using big words makes writing bad. It just depends on who uses them, how they're used, and the reason why they are used. Sorry my answer is long but I felt I needed to explain myself.