I’ve seen plenty of bad writing, and often it’s wordy. But not every struggling writer struggles with prolixity. I have had to learn to overcome the opposite problem: my writing is too short and leaves out intervening steps. My son is the same way. I look at his writing (or, now, his tutor looks) and say “Explain more. Flesh this out. Give details. Take the reader by the hand and lead her to your conclusion.”
Clarity in the kind of writing I do involves assuming that my reader doesn’t yet know all I know about a subject, and she needs me to explain it to her simply. That is also the kind of writing I like to read.