That's already captured in the basis of the option.
The difference is that if it expires worthless, and he's already paid tax on it, now he has a loss. It's better the way it is now: worthless options (the VAST majority of them) aren't a tax item at all. It's called an OPTION afterall.
Your proposal increases complexity without increasing revenue opportunities; and of course with AMT, some of this already happens (though as investment income, not regular income).
/jordan