IO540 gave a pointer there, I think. Private strip owners doing what they like -such as buying PCL sets and setting them to any old frequency because they don't have an allocated one, and causing interference with who knows what else uses that freq. The inability to control that alone would give the CAA good reason to say no. And you bet the CAA prosecute illegal use of frequencies causing interference with legal users.
Bit embarassing if you picked the same freq as the police base though, and your farm strip lights up lke a christmas tree every time they want to land, and vice-versa.