It doesnt need to "evolve" recursion is completely possable, it was deliberatly blocked by the designer, as his feelings (and likely research) was that the majority of users well find recursion more problems than its worth, so as to the "efficiency" well its not efficient if it causes a majority of users problems, no matter how wizbang the feature is for a minority.
The minority who might need it, (i have been one) well find working around the block placed on for the majority, hardly a difficulty

example code.
Code:
alias wordlengths {
  echo -a Word " $+ $$1 $+ " is $len($1) characters in size
  recurse wordlengths $2-
}
alias recurse { $$1- }


Now its one line extra for as many different aliases recurasing as you like and the word recurse infront of the recursing alias which makes it clear what your doing even!

* Side note : v6.16 has a fault in it that if u do start recursing the call depth check appears broken, you used to only be able to go down 1000 or so calls, right now it just crashes mirc at some point less than this 450 or so, but this appears to be a bug, that i assume well be fixed by next version. On this personally if your recursing that much then u likely could have done something different or should create your own data stacks, and stay with in the same call.