Comment by musicale

I kind of like "why didn't you just (use simple and obvious solution that doesn't work for some reason?)" If there's a simple and obvious solution that doesn't work and the reason it doesn't work isn't apparent, it's nice to know why.

On the more malicious side of things, one of the more effective ways I've seen people blast something to oblivion is "I don't understand how (your stupid system) solves (intractable problem created by your stupid system.)" Occasionally someone will twist the knife by prefacing it with "Maybe I'm missing something here, but...."