Eh, I could see the Commission doing it for protectionist purposes, but why would the highest Court care about that? If it's "protectionist" it's for EU citizens' data, not for economic purposes. I've seen no evidence to the contrary so far.

If anything, it's the Commission that has been much more willing to give the US government and companies "some slack" about collecting all this data. Luckily, the Commission's hands are now tied, and the ruling sets a rather clear roadmap for the minimum requirements of privacy in any sort of new EU law or agreement with the US.