Making up a weaponized quote that's close to what was originally said is actually worse, because then it's harder for passers-by to tell apart and more injurious to the original statement. By 'weaponized' I mean altering it to sharpen the point for indignation or snark purposes. It's a harmful internet practice that we've asked to users to abstain from.

You're right that it isn't explicitly mentioned in the site guidelines, but those aren't a list of proscribed behaviors but a set of values to internalize. I'd say "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize" covers this case pretty squarely.