This is a common "troll" mentality.

Truly they just get a thrill from getting a rise out of someone (and/or there's an economic motive, as is the case here), but they're able to post-rationalize it as a helpful service to their victims. They're pointing out areas of weakness; or they're playing 'devil's advocate'; or they're demonstrating the folly in engaging with an unreasonable person.

One of the things I find most frightening about people is that, generally, we all think we're the good guy.