Re: Isn't this a consequence of being in the EU?
Transfer pricing is at least somewhat clear with a company like Apple that makes (most of) its money the old fashioned way, by selling tangible goods. Companies like Google or Microsoft make almost all of their money selling intangible goods - and not even to consumers. Microsoft is selling 'software licenses' to PC OEMs who sell PCs to consumers, and Google is selling ad space targeted at its users to advertisers.
If a French resident/citizen buys €1000 in ads from Google to show to people in Paris, that's €1000 in revenue that can pretty definitely be claimed as earned in France. But what are the expenses? If Google doesn't have a datacenter in France and the ad team resides in Switzerland, should France argue that they have zero expenses in France and claim the entire €1000 as taxable profit in France? Google would argue they should allocate a share of their overall ad delivery cost.
It gets even more complicated if say I as a US resident/citizen buy ads from Google to run in Paris, or the French resident/citizen buys €1000 in ads from Google to run in the US. Or if Google has servers in France and maybe they are used to serve ads to more than France, or maybe they have an ad team in France that works with other EU countries.
Compared to that confusion, figuring out what taxes Apple should pay is simple.