There is a lot of room between "it's okay" and "it's slavery".
In this case, if "as needed" means "during the occasional launches of our experimental rockets, because launch windows happen at sometimes awkward times", it's quite a bit more understandable than "pretty much every deliverable, because we poorly set arbitrary deadlines."
Your initial point was good - it does not happen at "pretty much every" software company. I am not sure it's a red flag here, depending on the actual intent.
Sure, the only problem I see here than some people that work on startups think it's OK to force people to work overtime all the time - and for them it's the norm - where it should be an exception.
I saw it multiple times it even sometimes ends up with lawsuits like @ LinkedIn. I truly believe people can succeed without creating this kind of bad work culture.
In this case, if "as needed" means "during the occasional launches of our experimental rockets, because launch windows happen at sometimes awkward times", it's quite a bit more understandable than "pretty much every deliverable, because we poorly set arbitrary deadlines."
Your initial point was good - it does not happen at "pretty much every" software company. I am not sure it's a red flag here, depending on the actual intent.