I've recently found that all 'Which _____ character are you?" quizzes are very, very unoriginal; putting only direct choices of what those said characters would do or choose. It's beyond easy to guess who you will end up with, even if you answered truthfully. Most of the scenarios are from the show itself or have been written with little to no thought =/.
Sorry if that offended anyone, but I'm sure I'm not the only one that has noticed this.
Even so, I got Zoro; just like with my other 200 different quiz results.
I do agree with your point. These quizzes are indeed quite unoriginal. By putting more effort into it, it might be possible to pose questions about personality and character traits that go beyond "what would you do if a girl… (random sanji answer)", but then again that's pretty hard to create considering that anime characters aren't, and most of the the time aren't even supposed to be, realistic.