First, the press credentials should probably grant some benefit of the doubt if the justification for arrests is something along the lines of, "I can't think of any reason you might be here except to cause mischief."

I think what's shocking to people is that, traditionally, police have understood that they're somewhat more likely to be held accountable for abuses of power toward journalists. It seems likely that is primarily for the same reason that e.g. a tech company with a bad policy is more incentivized to fix it if it happens to stub the toe of anyone with an audience.

That police in many cases apparently knew that there would be no consequences if the press was _strongly_ encouraged to document frequent abuses is not a great sign.

The other parallel I think folks are drawing is that abuses of journalists in particular is a common feature of dictatorships. My sense is that this is not a particularly good parallel to draw in this case, but it's easy to see how one might connect the dots based on a passing review of the facts.