Google users in UK to lose EU data protection

Big companies which monetize end-user carelessness - yes. Facebook reputation has zero impact on its userbase.
Big companies which value their reputation and customer relationship - care very much about it.
Big companies which fall under regulated activity - care very much because regulator may stop their business due to non-compliance.

yes and no. the regulator can be bribed. man made laws are not perfect … but they do help … sometimes

Yes, once, or twice, but sooner or later it will become visible and will backlash with huge magnitude (see enron f.i.)