Not sure what you mean by "should" here, but the IRS definitely considers it to be a gain that you have to pay taxes on, regardless of whether you can sell the shares.
Yes, it's common. They'll say that it's because they don't want unapproved investors on their cap table, which I guess is reasonable, but obviously the main reason is "because they can".
1. You exercise your options, for a paper gain of millions of dollars
2. However, you can't actually sell the shares (there are likely contractual restrictions on selling them, and even if not, there's not a liquid market)
3. So you have to pay millions of dollars of taxes even though your cash flow is zero.
And before you say "but they're ISOs", there's no such thing as ISO's under AMT so it doesn't help at all.
I work at Scale - I've met a bunch of people that work on our platform, and seeing the impact that it's had on their lives is actually a huge source of inspiration to me. There's a writeup highlighting some of their stories at https://scale.com/blog/positive-externalities - based on my personal experience, I can say that it's not bullshit.
Most Americans have spare bedrooms for when guests visit. You could have your guests stay at a hotel but typically that will be really far from your home which sucks for everybody. Having Sonder or Airbnb style short term rentals distributed throughout cities could allow people to live in smaller apartments, eliminating bedrooms that sit unused most nights creating more space for everybody.
To be clear I'm not talking about the model of renting out your spare bedroom on Airbnb because nobody actually wants to do that. I'm talking about full time airbnb studios / 1BR's obviating the need for guest bedrooms.
The other, probably more important, innovation was that you have to take the picture at the same time as you send it - no loading from the camera roll.
This stuff is much worse than NSA data collection. Gag orders are evil, and secret courts are even worse. I really wish people would stop worrying about government surveillance - who cares what people know about you? - and start worrying about this instead.