Why Internet TV's will always be losing the battle against "Living room devices"

I keep seeing people talkign about Internet Tv's and they will eb the wave of the future taking over from Roku/Home Media PC's etc.

I cant stress this enough these seperate boxes will always have an advantage over "Internet tv's" in that they can be replaced on a regular basis every 1-2 years or so fairly cheaply; The average time for a TV replacement 4-5 years..... you do the math.

The CPU/smarts should ALWAYS be a seperate device to the TV...yes even if its an Apple TV.

Cheers,
Dean