That quote doesn’t apply at all. Verbose writing doesn’t immediately indicate a lack of skill, otherwise every fiction book would’ve been reduced to a pamphlet of a summary.
If you are writing to explain, being concise is a useful asset. If you are writing to entertain, or for pleasure, verbosity and flair can be better.
I don’t get the feeling the author is trying to convince anyone of doing anything. They are sharing their experience, probably writing for themselves above everyone else. They should do it however they prefer.
I was replying specifically to the statement that writing verbosely is a form of "skilled writing", which I don't agree with. Simply being verbose does not make your writing any better.