I agree that the current state of the company is important: if it has just hit traction and there are fairly risk-free payoffs for everyone employed to work 60-

I agree that the current state of the company is important: if it has just hit traction and there are fairly risk-free payoffs for everyone employed to work 60-80 hours, then the fact that everyone is working so hard might be a good sign--it could mean that everyone believes in the product and are bringing their A+ game. Additionally, if the market they're in is a fast-growing one, and it seems like it may be a winner-take all, then the effort can be justified. However, if (1) this company is still looking for a product-market fit, or (2) has been pulling this kind of hours for years, I would see that as a red flag. (1) seems to signal a frantic attempt by the founders to hit a milestone before they run out of cash, and (2) means you can expect this kind of culture for a long time ahead, which, as others pointed out, benefits the large stakeholders at the expense of employees.