Exactly because you really are not.

By the time you get diluted you effectively are a stockholder with way too much of your net worth locked into one likely extremely volatile company. If you are lucky enough to be in a succesful startup you still have to survive the inevitable whiplash when your liquidity frees up.

Ironically and sadly I have a couple old-timer friends who have been through IPOs where they have lost money on the whole damn thing mostly due to taxes and poor timing.