I would wager your codebase, tests and development environment reflects this. Any product of any significance requires a day of setup at least before you even get as far as cloning the repo and opening your first user story.
Well, first of all, ouch. Sure, of course you're right about "product of any significance" and I mentioned one myself in my post - Windows. The more complex the project/team is, the fewer people will be productive in 24-48 hours. So yes you can arbitrarily set the bar as high as you like for what "significant" means for you to be correct.