[Jtsummers]

Depends on the timescale and how captive the audience is. Oracle DB has a reportedly pretty bad codebase but a captive market that keeps them from needing to address the problems (as rapidly as their customers might like). If low quality lets you be first to market, that may be worth the later maintenance costs by gaining an outsized portion of the market and earlier revenue than your competitors.

On the other hand, if you've got an old system with poor quality code and can't make changes, your customer(s) are willing to drop you, and you have competitors who can get out the desired features, you're screwed.