"Via warrant or subpoena" You want American companies to ignore court orders. This isn't about privacy protections. You want EU data to be immune from court orders.
The USA would not accept their American companies to become subject to European subpoenas and courts, but does enforce these requirements when the situation is reversed. Obviously the EU doesn't like that.
Nobody wants American companies to break the law, the EU just wants American law to be better. America disagrees, and there's nothing wrong with that, but that obviously has an impact on the economic viability of the European market for American companies.