The problem is that the counterfactual isn't obvious. The company spends more time - and money - than they needed to fixing those issues, but how do they know? And how do they know that it would've amounted to less if they'd done those fixes sooner? Figuring that out, and figuring it out accurately, is often extremely difficult. A serious attempt might cost more than the fixes.

...and often the amount more isn't catastrophically more, so they don't even think about it. The company might be bleeding from paper cuts, it might be terribly unhealthy because of it, but still not unhealthy enough to kill it.