Most startups aren't valued at $1.5 billion, which GitLab was at the time this article was written. Once a startup reaches that valuation, it's already been mostly de-risked.
Ehhh but... $4,000 to exercise the shares? You have to be REALLY REALLY confident a startup is going to 100% no-soft-exit fail to not take that bet, given the vastly positive payout even an acquihire exit would give, given how cheap that strike price is.
$4,000 to exercise and $250,000 in taxes on shares that they wouldn't be able to sell for another four years. The AMT heavily punishes exercising options in pre-IPO companies.
In 2017 when making this choice, presumably the FMV would not have been anything close to what it is now, and there's little to no issue with AMT.
$4000 to exercise, but a lot more in taxes. Given that his shares were worth about 1/6 of what they are now, and assuming the FMV for tax purposes was about 1/3 that, he would have to pay income tax on $60k worth of paper gains. That's an additional 20-30k depending on the state.