"When fans are angry, we're selling comics."
Tom Brevoort, Executive VP, Marvel Comics
I don't think any of us expected the DC Reboot to be without controversy. The fundamental nature of a reboot means that amongst all the changes, there will be stuff that the fans don't like. Like the quote above says, that's a plus for the industry. Just think of all the free mainstream publicity Marvel got off of not only killing Ultimate Spider-Man, but rebooting the character as a minority. Pundits were flipping out, stories were printed in widely read newspapers, and sales prospered. Hell, even DC's pre-boot controversy of Superman renouncing his citizenship made the headlines. I bet that sold some comics as well.
Both these instances represent change causing controversy which in turn sells comics. Change To Sell is pretty much the mantra behind the New 52 - new costumes, new numbering, and new backstories abound. The poster girl for this philosophy is probably Batgirl as she's the character who has gone through the most change, casting off her chair and Oracle persona in favor of a return to her crime punching roots. I'm not a huge fan of the change, my librarian nature preferring the dedicated, behind the scenes hero Oracle to the building-swinging Batgirl, but I don't hate it. I can see why some people would want Barbara Gordon to walk and curiosity about the change (and controversy) caused me to buy Batgirl #1 upon release.
The anger over Barbara walking is the "good" sort of controversy that sells comics. However you may feel about the loss of a disabled superhero or trying to wipe away the stain of how Barbara was treated in the 80s, you could at least see some logic behind it. Even from a business perspective, having a walking, fighting Batgirl makes sense - it's only a matter of time before she gets her own movie, so the Idea Factory that is the modern comicbook best get to work now giving her her own identity and story engine.
There is a bad sort of controversy, though, one that goes against the quote above and actually does not sell comics, even though it makes fans plenty angry. This controversy may have aspects of change to it, it's not a change at its core - it's just more of the same.
I'm speaking, of course, of the treatment of female characters in the New DC. Changes abound here, but they are not core changes, just the logical extension of how female characters seem to be treated in comics. Harley Quinn to Juggalo, Amanda Waller to Tyra Banks, Starfire to fuck machine, all these "changes" represent a fundamental adherence to the idea that females in comicbooks are eye candy first, participants second, and characters a distant third. The anger felt by fans here isn't a "How dare they do THIS!" type outrage, it's a "Ungh, so they did THIS again?" type disappointment. The anger comes from the feeling that opportunity has been wasted, that there was a chance here for real change that was cast off in favor of more of the same, but somehow worse.
That anger is not the anger that sells comics. That's the anger that keeps comics on the shelf and makes potential customers roll their eyes as they walk by, tired of dealing with the pornification of the genre. I'm a guy and I don't want to buy these comics - I can only imagine how the Rule 63 Drew would feel.