This is the only argument I have found against Bitcoin that have substance. I can see this as a problem, but so far there have always been enough miners that was profitable. One day that might not be true though - hopefully it wont.

One reason for the halving cycle could be the way it kinda shocks the price and that makes people speculate and talk about Bitcoin like crazy. This is the perfect way to have a wrecking ball breaking the old broken system. Or it might just have been easier to implement.