I don't see why you'd say it's useless, though.
Because it's true.Since the fundamental assumption in Lisp is that everything is a list, I don't see how hashtables would actually work (as they are decidedly non-listy). But anyway.
Also speed is only a consideration for people with slow computers. If you want to let players create scripts, Lisp is most definately a poor choice.
If you had to chose a language other than BlitzMAX, try Python or Eiffel. Lisp deserves to die the peaceful death it was denied 40 years ago.