I would never advocate dumbing down your prose by avoiding "big words." Nevertheless, an avalanche of excessively latinate verbiage can have an obfuscatory effect on your potential interlocutors as well as being downright ugly. I would never say not to use a dollar word where a nickel word would do, but I would say that you should calibrate your vocabulary for precision and rhetorical efficacy. One common problem is the use of too many words ending in -ize or -ization.
One problem is that people use "big words" without knowing what they mean, confusing desultory with derogatory. Throwing verbiage at a problem is like throwing money at it.