Only if you value processing power over all else. And place no value in added portability.
I know this is a tired argument, but one last time.
1. 8Core Mac Pro. $2799.
2. 17" MacBook Pro. $2799.
The Mac Pro beats the MacBook Pro across the board on benchmarks. Therefore, by your logic, no one should buy a MacBook Pro. And if you are going to attach the computer to your desk, then the MacPro is more bang-for-your-buck. If you ever want to leave your desk with your computer. You'll gladly pay the $XXX premium for a MacBook Pro rather than try to lug around the Mac Pro where you want.
Similarly, for some people the extra 2 pounds of savings is worth the $XXX-$XXXX premium of the MacBook Air. Especially if they don't use their computer for heavy duty processing applications.
So while a 2 pound difference makes no difference to you if all you are doing is carrying around you MacBook from home to your parents christmas, if you are carrying it around every day with you, the 2 pounds is a big enough difference that it's worth $XXX.
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