"Strong opinions, weakly held" makes sense in exactly one situation:
When you are definitely an expert in a topic you should have your strong opinions about it.
But since everybody is sometimes wrong about something, and that should be very seldom in the expert case, you should be able to let go of one of your opinions, in case you get counter-arguments.
But since everybody is sometimes wrong about something, and that should be very seldom in the expert case, you should be able to let go of one of your opinions, in case you get counter-arguments.