This is not at all like setting up a special microphone to eavesdrop on someone. A person with a baby monitor would be broadcasting a signal onto public airspace with an amplified radio transmitter. If it comes into my airspace why can I not receive it using the same technology? Why does one person get to use publicly allocated radio frequencies and other does not? Is this fair? If the baby monitor broadcast on non-public frequencies it would be doing something much more illegal than me receiving them.

You are criminalizing receiving but not transmitting. I contend this is no different to yelling out of your window and criminalizing people hearing you. if you cannot come up with something other than 'it is wiretapping and private' to argue against broadcasting unencrypted radio into public airspace with a radio transmitter being by definition a public broadcast then I ask you not to respond because there is no answer to something like that, just as there is no answer to someone contending that listening to something people yell out of windows is a violation of privacy.