Food Safety essentially refers to minimizing the risk of contamination in the food product during processing. We cannot eliminate all risks, it is just not possible. Why?
Everything in the factory which is not the actual food product, e.g. equipment, building, etc. is a source of contamination. Everything in the factory which can move, e.g. people, air, etc. is a carrier of contamination. Hence, the Sources of contamination, and the Carriers of contamination are inevitable, and they simply can't be eliminated.
What is possible is to minimize the risk and manage the residual risk. Bad engineering leads to uncontrollable, unmanageable amounts of risk, while good engineering avoids the majority of the risk and manages the residual risk.
For example, a poor building design can lead to paint coming off and falling onto the product, pests/ insects entering from outside, water stagnating on the floor, etc. Whereas a good building design will provide smooth, robust surfaces, leak-proof building envelope, proper slope for drainage, etc.
For example, poorly designed equipment may render cleaning impossible leaving behind food traces after CIP or COP, and hence contaminating the next production batch. Whereas properly designed equipment will allow 100% cleaning validation in CIP and 100% access for verification.
The same with every infrastructural element of the food factory.
The ethical and responsible way for any manufacturer is to produce what can be served to one's own family. Only good engineering can make this possible.