You're kidding yourself if you believe the point of target shooting is to more effectively destroy bottles or cinderblocks.
Guns are missile weapons. They exist to kill. They do not exist to facilitate the destruction of mundane objects. Their purpose is inflicting death at range. They are designed specifically to end life. The fact that an operator can put a gun to uses other than the intended one is irrelevant.
After all, there are countless ways to break bottles at a distance. Any missile weapon will work, really, and there are countless far less dangerous missile weapons available for this purpose. Heck, most alternate options are substantially cheaper, too.
Yet oddly enough, you don't see nearly as many people taking up archery and the like as you do taking up shooting. Isn't that odd?
It literally costs nothing to chuck a rock or hurl an old hatchet from your garage or toolshed at a bottle, yet so very few people bother to take that sort of thing up as a hobby compared to target shooting. People instead go out of their way and spend vast amounts of money on attaining firearms. They must have really sturdy bottles.
Anything can be a weapon, but not everything is designed to be one. The fact that cooking knives can be used to kill doesn't change the fact that they are inherently designed for utility rather than combat. The fact that a firearm can be used to destroy a bottle doesn't change the fact that they are inherently designed for killing rather than sport.
This entire conversation started with a comment about guns being bad. They exist for the purpose of killing people. That's pretty bad. Yes, you can shoot bottles with them if you really want, but their intended and chief usage is killing people.
If guns magically ceased to exist tomorrow, it would be a lot harder to kill people. Bottles would still be just as easy to destroy, however. Net result? Human life is less vulnerable to the whims of the violent, emotional, distressed, confused, or misguided, and humanity's ability to shatter bottles is unchanged. That's what we call a "good" thing.
If guns were then magically brought back into existence the next day, people would be far easier to kill once again, and bottle destruction would again be unchanged. That's what we call a "bad" thing.