[goldcd]

I don't think it's solely the "price-tanking", it ties them to the company for a while.

i.e. If I was an investor looking to buy, I'd be a bit worried if the dev team would all be made instant millionaires on the day I bought in, with no incentive aside from salary to carry on working. You might find you'd just bought shares in an empty office.

[kgwgk]

Not being able to sell the shares you own is separate from not owning shares in the first place.