They are, but consider that they are very volatile. When I worked at Yahoo, my stock added an equivalent of about $50k/year to my total compensation for the period I worked there. But I was lucky - I joined at a low and left and cashed out all my options with Yahoo trading at one of its highest amounts of the last 7-8 years.
At the same time I had people working for me who had 10 times as many options, but had been in the company for ages and received the vast majority of those options before the crash in 2000. As of this year, the couple of those people who are still at Yahoo will have options worth maybe $30k-50k total from 10+ years of employment that are over water, and their older options will start expiring soon.
Of course Google people receiving new Google options now are currently in a better position, but estimating the value of options grants over time is tricky.
The issue is the same in principle - just less extreme in that barring a total meltdown you have an easier time assessing the lower end value of the package. But to take the Yahoo example: When I joined, a share was worth about 1/10th of the strike price of the bulk of the options of several people that worked for me. 1/10th would've been a lot better than getting nothing, but still.
You have to be careful when reporting them as part of compensation because they're difficult to value. Stock is easier in an already-public company like Google, although it is still subject to some uncertainty due to vesting schedule. The monetary value of being able to come into work at 11 is going to differ greatly among employees.
