Why is there no Long Snapper position in the roster?

Why is there no Long Snapper position in the roster, but there is in the depth chart? Couldn't you add in the Long Snapper position instead of just placing a really crappy Tight End or Center on every team? Or at least if you're going to put a crappy player on the roster who is the long snapper could you make them good at long snapping on the depth chart instead of the regular offensive linemen?

Also, is there really any reason as to why you should put a certain player in the LS position in the depth chart? Are there penalties for putting in a bad player at that position?