Two quotes from George Orwell spring to mind:

"The great enemy of clear language is insincerity. When there is a gap between one’s real and one’s declared aims, one turns as it were instinctively to long words and exhausted idioms, like a cuttlefish spurting out ink."

"If people cannot write well, they cannot think well, and if they cannot think well, others will do their thinking for them."

nuff said...?