I've yelled at my TV way too many times already this year: "A forward needs to cover for the ****ing D jumping in!" and every time, it turns into a 2 on 1, or a 3-1, or 3-2. This should not happen at the pro level, because as you said, it rarely happens in our men's league games.
It's like our D got more active, and/or got a longer leash with activating in the O zone... but the forwards just don't pay attention to it, and odd-man breaks are the result. It has happened with Seabs numerous times. He's up on the rush in like a 3-2 with two forwards, and the late forward keeps breaking down into the zone down low... leaving one D sitting back by himself. Pick your head up and look around. If a D and two forwards are in an odd-man rush... you have to stay back, as the third forward. This all depends on the personnel, also, obviously.