Not all European CAs meet browsers' root programs requirements. Forcing everyone to accept those certs weakens all root programs (Mozilla's, Microsoft's, etc).
There is also the concern that special indicators displayed with a certificate can mislead users. A scummy company with an EV cert isn't any more trustworthy than if they had a DV cert, but browsers want to be careful not to imply a fancy logo makes the site any safer.
Not all European CAs meet browsers' root programs requirements. Forcing everyone to accept those certs weakens all root programs (Mozilla's, Microsoft's, etc).
There is also the concern that special indicators displayed with a certificate can mislead users. A scummy company with an EV cert isn't any more trustworthy than if they had a DV cert, but browsers want to be careful not to imply a fancy logo makes the site any safer.