You could as well have said:
2013: pre-Bay Trail era
2014: Bay Trail era
Contra-revenue has nothing to do with anything. If Intel didn't have contra-revenue and BOM issues, they would have won just as many design wins.
And your claim that AMD is more efficient than 22nm SoCs is simply impossible, and verified by power measurements (single core Cinebench is 0.85W, which is in fact lower than AMD's idle power consumption).
Without contra revenue they wouldnt had shipped that much chips even if free, at 0$ they would had retained 70% of the market thanks to a massacred price but to get about 100% they had to pay 60$ plus a chip per delivery unit, at thoses conditions the OEMS saw an easy way to cash some money while it last, just imagine that Asus or HP net margin is 8-12$ per 200-300$ laptops, this price being the OEM price, to compare to the free chip + 60$ subside.
As for Mullins it s a better chip overall than BT, you dont realize that it gets twice the graphic scores at same TDP or so, check Anandtech review with the comparison with Asus s T100 wich consume likely significantly more.
