If you winder why we get trapped inside our zone for extended times, just watch Martys strategy when we lose possession in our zone.
We go into a tight zone defense which gives almost free rein to the opposition to exploit their skating and passing. That's also why it looks like we are on a penalty kill...with 5 man.
So man-on-man near the blue line, zone if we lose possession...and a lot of praying in between.
Now imagine if you are a forward trying to support another forward? You have to judge when to go in for support and when to man yoir position. Confusing as all hell, particularly to young guys.