Sure anyone can just click presets, but performing with Milkdrop visuals is just one piece of the puzzle. Layering it with pre-rendered custom visuals is another piece that heightens the art form. And then the actual performance of matching the mood and changes in music, it's a skill that is difficult to master when performing live and juggling many different aspects. Combine that all together and you have something that takes an artists eye to pull off in a polished fashion.