For some bands, the opportunity for abuse is low because it's only allowed to be used at low power or for voice or other limitations that don't scale up much. B

For some bands, the opportunity for abuse is low because it's only allowed to be used at low power or for voice or other limitations that don't scale up much. But cellphone data has more demand than the spectrum can provide. If they didn't charge users, some people would try to hog all of it and ruin it for everyone. Same goes for broadcast radio transmission. Access has to be restricted somehow. If not by payment, then probably something that makes less efficient use of it like non-transferrable first-in-first-served or lottery.