Yes, and Batman is on the JLA too. So the next time he has to get from point A to point B really fast, he should use the teleporter, right? And the JLA needed to be there, helping put No Man's Land right, right? The next time Ra's al Ghul does one of his big ecoterrorist plots, Batman should phone up Superman, right?
The shared universe is there for the occasional fun team up. It's there so you can go "what would happen if Aquaman and Green Arrow fought Poison Ivy?"
The shared universe becomes a problem when people start introducing things that don't fit individual books' tones, going "well that's how it would work in Metropolis!"
In Metropolis, the police get jetpacks and robot armor. In Gotham, the police get a badge and a gun. If Coast City suffered a plague and natural disaster, the JLA (and probably Green Lantern Corps) would be there to fix everything and kiss everyone's boo boos. In Gotham, the JLA aren't invited. A formerly-disabled cyborg works fine in the Teen Titans. But someone like that shouldn't be Batgirl. And teleporters may be a good idea in JLA, but when Batman (or Green Arrow, or Black Canary) has to get to Tibet, it should be a hassle. The shared universe is nice, but not worth shoving high-sci-fi permanently into books where it doesn't belong.