According to the Google tanslator, this is more or less: "er ... I reckon me that your poll is biased, because in life everything is not all black or all white. You see, you've got issues that should be several levels of assessment, not just "all true" or "completely wrong" Finally, I'm going from a forum that will be called: "Bashing Forum forums suck."
I think the poll has some validity. There are five questions to rate the store on, so that gives a good idea of what the store is like. I see a benefit in the yes/no format: it keeps things simple (yeah, maybe too simple), so that scores are easier to combine.
That being said, I think it wouldn't be too hard to do as you seem to suggest, and provide a scale of maybe three or more levels (Bad, OK, Good).
Of course, it's all pretty meaningless if only a few people cast a vote.
Also, there is a selection bias because mainly people who are unhappy with CTC come here and rate things.