I'm saying compare apples to apples... a parade with probably 100+ specialized cast involved is not comparable to a show ran from a control booth.
Fireworks? that's an easy one... fireworks are freaking $$$ plus all the labor to reload the show. On top of the labor, how many pyro crews do you think Disney has on staff? They can't just say "ok mr licensed, regulated pyro guy.. please work a double shift" carte blanc.. and they don't have the type of duplication in staff in those kinds of roles to the level they do attractions, etc. So it becomes a lot more expensive, and not just the shells, but who and how long you need them.
Running more fireworks shows is a pretty intensive investment. If they are willing to spend that or not, of course is a choice.