The problem is, money loss through poor software quality is (and maybe can) not be calculated in a way that, for example time (for development) can be measured.

The problem is, money loss through poor software quality is (and maybe can) not be calculated in a way that, for example time (for development) can be measured. Often the arguments for increasing software quality, for example through refactoring parts of a codebase, are therefor not fact-based, but mostly vague. This is often not enough to encourage the decision-makers to invest in good software quality. Apart from that some people might deliberately choose to not care about good software quality. But in my opinion this is often a sign of missing/poor education/experience.