It's really the software. It isn't made to host lists. Votes on lists are historically on the item (OMG YES JQUERY!!!!!), not on the answer (You should use jQuery because a. b. c. d.), and that isn't how the rest of the site works.

Besides in a Q&A network, a "list question" has "list answers" where every "answer" is a "list", rather than an item of that list. Even that doesn't really work because that's not historically the way the site is actually used.

See also the following for the rationale:

http://blog.stackoverflow.com/2011/01/real-questions-have-an...