The fundamentals of the situation are that the police have to actually do things - or take the responsibility of not doing those things - whereas journalists never do things and if they change their minds about what they said yesterday they can just change the subject.The police are susceptible to second guessing, just as any private business which actually does things is susceptible to second guessing. The idea that journalism advocates big government is not quite right. Journalism advocates journalism. Journalism is self-interested. It is no more a surprise that journalism promotes Al Sharpton criticizing the police than it should have been that journalism edited the Rodney King arrest tape down only to the part that made the police look bad, then endlessly repeated replays of that part.
Journalism promotes itself by propagandizing against everyone who, by doing necessary things, might manage to earn a good image. Controlling image is what journalist think is their turf, and you are not to be allowed to earn a good image with deeds. You can only earn good PR by promoting journalism by secong guessing people who do things.
Journalism is cynical about everyone else; the only rational thing for the public is to be cynical about journalism. Journalism has codes of ethics; you read those codes which tell what journalism promises not to do - and expect that that is precisely what journalism will do. Routinely.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." -Manuel II Paleologus
I don't think journalists are just interested in job security. They have a political agenda which, by and large, is left wing.