How would you suggest they express their disapproval, if not through the legal system? I'm personally not opposed to holding conpany executives personally accountable, including jail time in severe cases, but I don't think this would go over well with the US government.
The fines seem to be low enough to be a Cost of Business while not high enough to actually force behavior for the largest companies.
While the personal accountability would be nice but is political infeasible, I wonder if the EU could revoke business licenses to remove US companies access to the EU market.
U.S. citizens are arrested and convicted for breaking laws in other countries all the time. It's rare that they get out of it because they are a foreigner. It doesn't matter if the laws and punishments are different - whether that be a caning for spitting, a prison sentence for besmirching the king, or even the death penalty for drug dealing. People are obligated to obey local laws, even if they disagree with them, or suffer the consequences.
Not saying there can't be an international uproar, but if laws were broken the local justice system is legally entitled to punish the perp, even a foreigner.
People loose their minds for all kinds of reasons, I can't speak to that ;-)