Illustrator does, indeed, have a History.. that is your "Step backward" and "Undo" However, it's not used the same way as in Photoshop, (apparently hasn't been, for quite a while), and is not used quite the same way... so it's not available to purge any longer. It seems that, the way they are using it for Illustrator is "lighter" on system resources.

  Actually, it's still true.. they prefer Scot Scotts, or Scottish, rather than Scotch. Sorry, that was a faux pas on my part. Lou.

"..... and that was when things got interestiing."