The guy doesn't know crap.
I actually prefer either no rear speakers or low volume on rear speakers cut at 3K-4K. It helps to anchor the soundstage up front. Just imagine it like you're sitting at a concert listening to a band. Do you really want it to sound like they're playing behind you?
Bass is a whole other story as it becomes omni-directional (no point source) below 80Hz or so.
Anyways, if coaxials in the rear deck is what you prefer, go for it. They're your ears. Gotta make 'em happy.
