Not sure why the OP needed to post a thread on this, but this happens on all flights and all airlines and in both J and Y classes.

When an entire plane of passengers gets up to exit, there is limited aisle space and it will be tight. @:-)

Why some people rush to the front, there could be a number of reasons, including a tight connection, need to get some air, trying to catch up to someone in the front cabin.

Perhaps everyone should relax and you will enjoy the flight and day better.