In interviews at the time, Miller didn't say Batman was "goofy," but he did (rightly, I think) say that his edge had worn away. Actually I think his exact quote was that he'd gone "fat and happy." If you can imagine Bruce Wayne cutting his lawn on the weekend, I think he said, you've lost sight of what the character was supposed to be.
I appreciate Miller's DKR for what it was -- an Elseworlds-like possible future. The real problem came when scores of lesser talents came along and turned it into the "official" version of Batman, stealing as much and as often as they could and ushering in the era of "Bat-Jerk."
That said, there was a wonderful period in there, post-Miller and pre-Knightfall...just a few years...where the books took a real uptick in quality, between Chuck Dixon's work on Detective, Grant and Breyfogle on Batman and 'Tec, and various other neat things. It took a while for things to spiral out of control irretrievably. By the end of "Knightfall" I was gone.
I actually don't know that I've heard anyone suggest Miller "saved" Batman from goofiness, but I do think it's fair to say that prior to his mini-series, Batman was still, in the minds of a lot of people, still stuck in 60s TV mode. But that's because they hadn't been reading the books. DKR was the first Batman project since the 60s to get media attention, so that's probably why so many people don't remember anything in between. Then the Burton films came and got even more media attention, so often HE'S the one credited with "returning Batman to his dark roots."
I don't let it bother me. Whatever happens, I've still got my beloved back issues. Like, to bring this back on topic, this one (courtesy Marshall Rogers and Terry Austin):













