That's a pretty simplistic explanation. There are lots of ways to mess up Lisp in an attempt to enable the style of meta-programming that Kernel supports. What distinguishes Kernel from these other approaches (many of which have been seriously considered in the past) is mostly what you're not able to do in Kernel. That is, the vau construct still allows encapsulation in a useful way. Kernel may have "more things first class" than Lisp, but that's not all that sets it apart.