I'm using PA drivers and horns and cabs (Peavey FH1 bass horn) in my main system, but the difference between a hi-fi setup and a pro PA set-up most often lies in the crossover. If you're after max SPL you probably go with different frequency crossovers and slopes - to protect the drivers from over excursion or over heating - than when your goal is maximum fidelity and smooth transition between drivers and phase coherency. That makes a HUGE difference.
Still, I'm sure that there are pro speakers that could be used in a home environment but those are far from the majority.