Normalization is nice for a mental exercise, but I cannot buy a normalized phone with a normalized i7 that fits in my normalized pocket. Engineering is the art of trade-offs and the i7 has traded off size and power to achieve speed. That is great when you have an i7-scale size and power budget, but if the i7 exceeds your power or size budget it is a non-starter regardless of how efficient (when normalized) it is. Full stop.
The implicit argument of the paper is that Intel could produce a direct size+power+speed replacement for a phone-scale ARM processor, they just need to dial the knobs to small+small+slower. The counter argument is that they have tried but not come close. The Atom line is roughly comparable with respect to speed, but size and power are a problem. The Galileo processor is roughly comparable with respect to power and size but speed is horribly lacking.
There are x86 phones on the market that have similar weight/shape/battery life to ARM phones. Anandtech reviewed one two years ago and found it in the middle of the pack with respect to energy.
The question for Intel is dialing down the profit knob: how much of a hit do they want to take on each unit shipped, by competing with ARM for tiny phone chips.
The implicit argument of the paper is that Intel could produce a direct size+power+speed replacement for a phone-scale ARM processor, they just need to dial the knobs to small+small+slower. The counter argument is that they have tried but not come close. The Atom line is roughly comparable with respect to speed, but size and power are a problem. The Galileo processor is roughly comparable with respect to power and size but speed is horribly lacking.