For the specific subset of people in tech, I don't believe this is true. How many times have you and someone else had a strong disagreement about the cause of a bug or design of a system, conclusively determined that one answer is correct, and then had the other person come back (usually after a small delay) acting as though they'd agreed with you all along? I've been seeing this for over thirty years. Half the time, the other person even tries to claim they came up with the idea on their own and everyone else was slow to pick it up. Same thing is frequently evident right here. It's easy for some people to switch from one strong opinion to another, and the popularity of "strong opinions weakly held" makes it even easier.
I also think that SOWH is behind a lot of cargo culting and conspiracy theories. People want to get credit for being the champion of an idea, even if they don't fully understand it or it has low odds of being correct, and the appeal increases with the challenge of convincing others. After all, if they're wrong they can just switch sides and claim they'd been on the right side all along. If they're right, it's an epic victory (in their own minds at least).
Strength of belief is not inherently virtuous. It should be proportional to strength of evidence, not armor worn for the sake of a silly maxim. Strong belief in SOWH itself is an example of faith over empiricism.