I've avoided TDKR for a long time. Never read it. I know what happens and have had discussions about it judging by the characterization in how Superman in interpreted, but never read the story in all its script and context. I finally bought the TPB just yesterday and will finally be reading it cover to cover soon.
Though, the only reason I can think of other than Miller hating Supes is how people viewed the several decades of Superman clearly #1 on top and how untouchable he was goes in translation and is in parallel of how people are getting sick of BatGod nowadays. Superman was always the macho type, the cool and handsome hero with bright colors and calming smile..always there to protect while Batman was always the nerd with the butt-boy sidekick. TDKR was a ploy to change direction, humble Supes and make Batman a more serious contender within' the ranks. Superman was used and was the sole creation of BatGod...so you're welcome, Bat-fans.
Without the need to use Supe's as a Government pawn, the badass known as Batman wouldn't of packed the heavy punch he needed to jump the shark and climb over that hump. In many ways, though Supe's and his fans have to swallow their pride while reading this book, we still can smirk that it took our hero's sacrifices to really kick off Batman's highlighted popularity. Bats couldn't do it without Supes IMO.