So why not take iPad design mentalities and slap it into a computer? Because the iPad experience was engineered for the iPad. Simple interfaces are necessary due to the nature of touch devices, and usage patterns are designed for the form factor of the iPad. Dumping all of that into a PC because "Users are dumb, but they are smart enough to use the iPad" is missing the point entirely I think. If the same people are involved in both efforts, then I think either they have lost their focus, or I am giving them too much credit to begin with.
iOS is good. OSX is good.
The attitude "OSX is too hard, we need to make it more like iOS" is my concern.
If you can create a legitimate case for making changes to OSX that look like iOS features, then by all means do so. Natural scrolling direction is a great example of that, I remember wishing I could make my touchpad in linux do it 5 years ago. "Users are dumb" is not a legitimate case though.
Power users might not like some of the changes, but it's easy to provide them with advanced setting options to change them back (like scrolling or Gatekeeper)--or build the new features in such a way that they're easily ignored (like Launch Pad).