Sure, but good code saves time even on really short timeframes. Every time I've worked on—or seen other people work on—a "we must hurry at all costs project",

Sure, but good code saves time even on really short timeframes. Every time I've worked on—or seen other people work on—a "we must hurry at all costs project", enough time is wasted on debugging, firefighting and friction that just building a decently clean system from the get-go would have been faster. I've seen this unambiguously on "throw away" data science code meant to produce a single report (or normal science code meant for a single paper), and that's a much shorter-term effort than anything at a startup. The tradeoff is even clearer once you start working in weeks and months, much less quarters or years.