The problem with not having the central column is that if the drinker does not know how the cup is designed, they most certainly will spill all their drink. If the user brings the cup to the mouth with the internal pipe closest, the cup will empty. The reason for the central column is that when the cup is brought to the mouth the water level will not rise above the top of the internal pipe. The designer of the first cup probably had the tools to build the pipe in the walls of the cup but choose not to. I designed my own column-less cup not thinking about this and learnt this the hard way.