I've found this is a phrase loved by those who enjoy argument for its own sake, and who don't have a very deep understanding of a particular subject matter.
> Saffo’s original idea is so quotable it has turned into a memetic phenomenon... ‘Strong Opinions, Weakly Held’ turns into ‘Strong Opinions, Justified Loudly, Until Evidence Indicates Otherwise, At Which Point You Invoke It To Protect Your Ass.’
