The point is they should get out of their way on their own instead of taking up the whole aisle.

It's the same as when you're walking in a busy city, don't stop to talk/figure out where you are/take photos right where you are, kindly move to the side of the sidewalk to allow others to pass. Being aware means you shouldn't need people to tell you when you're in the way, you should make the effort of taking two steps to get out of people's way before it's ever an issue.