Can you blame them? These are the same teams who typically refuse to adopt practices that would allow them to create tests and we'll encapsulated designs. So inevitably the team is once bitten twice shy about breaking production. Why be the poor bastard who introduced anything but the tiniest bugfix?
I definitely agree it's a matter of incentives. Even in an environment with a now healthier quality culture, fixing bugs to bring an old system from 70% functionality to 100% is typically a career dead end.
It's much better to leave it broken and build a new system with 105% functionality so you can take credit for the whole 105%.
And typically, optimists that we are, it seems like completely reimplementing the original functionality will be "trivial" compared to merely trying to understand how the existing solution works.
