Given that protectionism is stupid and protectionists genuinely believe that they are doing something good for their nation when they implement protectionist policies I can use Hanlon's razor and assume both.
"protectionism is stupid" can be used as a generality, but if you make it a broad, confident assertion you're removing human judgment and trying to apply simplistic rules to the world — which is exactly the type of thinking that makes bureaucracies stupid.
And yes, with Hanlon's Razor, you can still criticize things that you accept as likely coming from good intentions.
And yes, with Hanlon's Razor, you can still criticize things that you accept as likely coming from good intentions.