ORIGINAL: britbrat
It is legal in Canada & the UK -- there are no "bleed over" problems, despite other users on the assigned bands. It seems that the FCC is over-zealous in guarding its turf, or it is a CYA exercise.
Are you citing actual studies or just a lack of any reported problems? I for one like the fact that transmitters need to be sent to a licensed technician for frequency changes. It allows them to ensure that the transmitter is operating within spec after the change. It also ensures that when the crystal is changed, that the frequency number on the transmitter is also changed.