most of the employees came in at later rounds, so play it out. ex: They'd get say $100K in options on paper, but the pitch would be the company is high-growth, so expectation of 2X, 10X, 20X, etc over next few years. That $100K is really $200K next year, $2M the year after, etc.
Except they sold the company at a ~flat multiple over the valuation. If employees got RSUs, then at least they made say $65K after short-term capital gains (30%+). But if as options... no growth over the latest valuation's strike price, so nothing. $65K is not $200K and certainly not $2M.. and $0 is even worse.
FWIW, I'm a happy customer, am happy for the founders, and hope the new features keep rolling out through the acquisition -- our usage of Loom grows every month! The issue here is not the founders, but HR & VC. This is why joining companies with high valuations is a big risk as the VC's have already set inflated prices that ate your potential payout -- you earn on growth over the strike price at time of joining -- and these high markup companies have a lot of revenue to grow into.