There is no shortage of software jobs. There are plenty of opportunities to work with a relatively clean codebase, capable and experiences colleagues, unencumbered by the VC runway bullshit.
Every company begins somewhere. If you want new companies to make it, allowing for there to continue to be 'plenty of opportunities' in the future, then accepting that there are times when repairing the ~sins~ necessities of the past is reasonable.
600 line bash scripts are not always necessary for new companies to make it. Sometimes, sure. Often, even, on the way to understand what is actually needed.
Many new companies spend too much time perfecting the wrong thing.
But messy code is NOT a requirement to make it.
Messy code, in and of itself, does not help.
Messy code might be a sort of inevitable step on the path to product/market fit. However, it is most certainly not a goal, and dealing with messy code is not a luxury. It is more likely a sign that the early tech people weren't very good.
There is no shortage of software jobs. There are plenty of opportunities to work with a relatively clean codebase, capable and experiences colleagues, unencumbered by the VC runway bullshit.