Readied actions in general are pretty ridiculous. Whoever's idea was it that every creature in Golarion can inherently see up to 3 seconds into the future without magic? Would say that this is an odd result, but it isn't, because NO usage of readied action makes any more sense.
A readied action isn't magic, or any kind of future sight. It's the result of planning. "I will ready to attack the next enemy that comes within my reach." How is that any kind of magic? Also, if no enemy comes within your reach, your action is wasted.Think of it this way, you're watching football and the team you're rooting for is driving down the field and it looks like they're going to score. You wait for the score to happen before you jump up and cheer, or basically, you "ready to cheer when you're team scores points". It's pretty straight forward, no magic or future sight needed.