There's a ton of criticism in this thread but I think people are missing the point.
1. Why 90 days expiration sucks.
If you're an early employee at, say, Uber... your options have vested but you can't afford to exercise them because you don't have $10m+ in cash. If you leave you lose it all because you can't exercise them. There goes your big payout, you are stuck working at Uber until they IPO (or forfeiting your equity).
2. Why 10 years expiration sucks (on its own, keep reading!).
Consider the case where you have two employees who joined on day 1. Employee A works for 4 years and vests X% in options, leaves. Employee B works for 10 years and vests X% in options.
Obviously you want to retain your most senior employees and turn them into leaders within your company rather than see them leave. Those who stay and help carry out the mission are way more valuable to you than those who leave right when they vest.
If you change nothing except 10 years till option expiration after leaving, employee A and B get compensated the EXACT same thing despite employee B contributing 10 years and employee A contributing 4.
3. Longer vesting + more equity fixes everything
If you dish out more equity over longer periods of time then employee B would rightfully be compensated more than employee A.
I don't understand the negativity in this thread whatsoever. Can someone please level-headedly explain why they disagree rather than just downvoting into oblivion?