[scarmig]

You write crappy code to meet unrealistic deadlines, you get promoted, hand off shitty code to someone else who is viewed as a low performer because they were too busy writing good code.

It's not actually that clear cut (it's more like an average performers who write shitty code quickly will be rewarded over an average performer writing solid code less quickly), but code quality isn't legible to management and HR, who control resource allocation. Even a line manager knowledgeable about the code base has incentives to lead a team that produces shitty code now instead of good code later.