The title is not perfect, the article talks about startup co-founder quitting, not an employee. For an employee, "anytime" is acceptable. For a co-founder the answer, IMO, should be different.<p>A founder quitting usually means the end of the startup and that means that founder quitting also affects other founders and early startup employees (for some it may create visa headaches). So, rather than a blanket "anytime" a co-founder should be clear to at least the other founders. And, if other founders feel the same way, to the first employees, too: a generic "we need to get to N users/ARR X/profitability/whatever within M months for the startup to survive" is sufficient.<p>Also, it depends on whether a quitting founder wants to try again. A startup failure on a resume is not a big deal for a founder, at least in the US. But being the founder who bailed on a startup that other cofounders thought could have made it is likely a big hit on the ability to raise money as a future founder. My 2c.