You have to look very closely at what the definition of "flawed" is. The dictator rule in Arrow's thm is not what it is commonly portrayed to be. All it says is that there should be no voter whose preferences are the same as those produced by the choice function. That doesn't really sound all that objectionable. Often people word the dictator rule as "one person decides the outcome" but that is not what it is at all.

And like the other response said, the fact that no scheme is "perfect" doesn't mean all schemes are equally flawed.