I had assumed that players would most likely be using gravity hammers to get into those enterances. Jumping on heads is not nearly as effective as beating down the gate, as once you beat down the gate, you can just run in every time you spawn, getting a more constant stream of players. In a way, it was overlooked (I had assumed on grav hams), but it is also not a great problem, to me. If you have been seeing everyone using those instead of the normal enterances, and you dislike it, just block em off in forge. Takes 2 walls and 2 seconds.