> there’s no such thing as a secure computer system

Where is your source for this? It is entirely possible to make a secure computer system, though it does require effort. The article specifically mentions "up to" 10% and the fines applying to companies leaking data on purpose or through negligence. I doubt the fines will be nearly as high for a company that tries to secure a system (and thus prevents more leaks) rather than a company that does not try to secure a system (assuming that leaks will occur), if the same breach happens.

Computers are deterministic (excluding cases where practically impossible cosmic ray events occur), so while we have the power to ensure system security, we should ensure system security. Heck, even just encrypting consumer information and protecting just the keys to this data would already decrease the effectiveness of many data breaches.