Although exceptions were made for the already highly popular stuff like Grant Morrison's Batman and Geoff Johns's Green Lantern, which were allowed to keep their continuities and story arcs largely intact.
Of course Morrison's stuff doesn't really impact the current Batman comics outside of Batman Inc. much and whatever does is pretty easy to explain I mean Batman #1(2012) pretty much covered a decent chunk of it anyway.
Though I don't know about Green Lantern as I haven't actually been following that.
Ronald Held wrote:
Continually rebooting the DCU shows how things have changed for the worse over the decades.
Or it shows that people are more interested in making money instead of minutia that only a small chunk of fans care about