The term "nerd" was interchangeable with "loser" in the past. These days? Not so much. However, when Ollie calls Batman a nerd, he's certainly not complimenting him, rather pointing out that Bruce's socially inept, gadget-obsessed emotionally stunted manchild shtick isn't nearly as cool as he thinks it is. Hell, most of what Batman does is a pubescent boy's idea of what a "cool guy" would be. As crazy as it sounds, Batman has been one of DC's biggest nerds all along. We just didn't see it until know, but now that Bendis has pointed it out, I can't unsee it.
Is Batman what people thought a nerd was in the 1980s? Hell, no. But people back then thought that feathered mullets, shoulder pads and lots of cocaine was the height of cool, so maybe we shouldn't be giving their opinions too much credit