ClydeFrog, do you know if the shop and promotion the DJ criticized was advertising on his station? If so, that would certainly annoy management.
In any case, as others noted, station management making a business decision is not government censorship. If the DJ, by voicing his opinions, had a bad enough impact on their profits, then he may suffer consequences he should have expected.
With regard to your comment:
I, for one, disagree with the radio DJ's firing if he only made remarks or voiced his own political views. As long as he was open & accepted pro-gun/2A messages or remarks he should be allowed to work on air.
the thing is, he didn't voice his own views at his own place, on his own time. He voiced those views on his company's time, on their transmitter, which effectively linked their business with his views.
Try using your place of work as a soapbox for some viewpoint your employer does not share, and see how soon you are searching for a new job.