I don't think it's cheap. That's like saying Thunder Wave is cheap because it always paralyzes or Spore is cheap because it's a guaranteed sleep move. There are plenty of ways to counter it, including Knock Off/Thief/Embargo/Trick/Disable, etc. and if you have a Pokemon like Spiritomb with the ability Pressure, you could Protect and Spite until Air Slash is finished. But everyone is entitled to his or her own opinion ;)
What would make this even more annoying would be Thunder Wave, so that you can always (unless there's a ground type or Trick Room) strike first. I'm thinking about trying this out myself :D