Why have guest players

GUEST PLAYERS QUESTION:
When and why did NTSSA allow for club teams to use guest players during league play?
I can understand for tournaments but come on lets think about this. Coaches will promise everything you want to hear to get you on the team. This helps the club make money. We all pay the same amount of fees. When a guest player starts and gets more playing time then the players on the team why don't the coach let the parents know so we can break the contract and move on. Does the coach have my thirteen year old best interest at heart or is it about standings at this point? They all say they develop players but doing a couple of drills and then scrimmage against each other is pointless. The coach dont have to teach at practice beacause they know they will have guest players. If they can develop players then they don't need guest players. This is like having an NFL player playing in a college game.
Let's get it back to how it used to be and you play with what you have. Good coaches will rise bad coaches will fall.