I disagree. Your statement is similar to saying, "Polls tell us nothing because everyone who participates could be lying and there's no way to verify their answers on an individual basis."

I agree that the list is not perfectly accurate, but I do think it's a decent indicator of the truth. When large amounts of people willingly volunteer information about themselves (especially if they think there's potential for personal gain) I'd estimate the margin of error to be closer to 0% than 100%.