Pirate radio is a lot less fun to run if you need it to be two-way.

Because you need your customers on the ground to run their own pirate transmitter (which can be located and penalized by ground authorities), and your satellites need to receive signals from the ground - which ground authorities from first-world countries can make arbitrarily difficult, deciphering a multitude of <1W transmission from customer cellphones is kinda difficult when a modern electronic warfare radar transmitter is tracking your satellite at the same time.