Right to define is not right to waive
The right to legislate in this area stems from the EU Privacy Right and Data Protection rights. A right to legislate to PROTECT something, is not a right to legislate to REMOVE those protections.
Just as the "Right to Life" doesn't permit the EU Commission from legalizing murder.
You can't have a blanket agreement with the US, the individual companies need to comply with EU law, because the promise from the US has been shown to be worthless. This is not a big deal, its affords EU the same leverage that China and Russia get with these companies that also operate in their territory.
So why would you give away our leverage anyway? I realize that Snowden revelations reveal a system of surveillance + leverage against you, but you can't turncoat in secret now, we know the deal. So why not stop pretending to do your jobs while undermining us, and instead actually DO your job?