If more people understood how they work best -- really, they should be called a 2-way -- they'd be okay. Unfortunately, intelligence is not required to obtain a driver's license.
I assume that you're referring to the fact that when 4 cars approach one from all points of the compass, N will wait for W who'll wait for S who'll wait for E, when N+S and E+W should just alternate.
Problem is, the number of jackasses who never use their turn signals ever. If you are headed N, one of these jokers headed S will inevitably assume that it's his turn, will gleefully turn left without signalling, wreck your front end and then blame you because it was "his turn."