Using the outdoors as a bathroom has been around that long as well, that doesn't necessarily mean that we continue to use that system. (unless, of course, it is during a frat party)
I'm afraid that I am not a fireworks fan, but, I know a lot of you folks are. I'll just say this, unless Disney decides that it is too dangerous to use live fireworks OR too expensive, they will stay put. Once they have reached both those items then will disappear faster then the speed of light.
I don't see them panicking over the two minor problems that they have had recently with them. I remember a situation a few years ago where there was a fire problem at the Castle. Yet, they continue to go on and will as long as the benefit outweighs the problems.