Have seen this far too often. I was at a successful UK based startup very early on, so my strike price was pennies. Those who joined a year or two later were looking at strike prices in excess of £30 with hundreds shares. Recent investment rounds put the share price at around £120, but as always current employees can't sell until a full sale or IPO.

The result? A swell of employees who want to leave/move on but can't afford to buy their shares and leave. It's lead to a number of people just hanging around, even when their enthusiasm and passion is waining.

Not what options are designed for!