Because judgements are arbitrary and in practice unfairly hurts foreign companies.
There's an analogue that has happened in the U.S. Let's say that my little white town passes a law that forbids jaywalking. Protects pedestrians... Makes it easier to drive... Sensible law right? But in practice, it's the 1940's and the cops ONLY ticket black people. In practice, it's not a law against jaywalking - it's a law to drive out all the black people and make the white town inhospitable to anybody with skin tone.
GDPR claims to protect the people but is used as an economic weapon.
