I think it is highly debatable if pre-new 52 Bludhaven worked. There was nothing to compare Dixon's Bludhaven to since this was Dick's first solo series, but I think as time went on and we saw more Bludhaven it revealed a lot of problems with the whole concept. Nightwing wasn't a successful solo character because of Bludhaven and he would have been successful in nearly any kind of solo setting because the character was already well liked, but now many think that Bludhvaen is tied to his success when I think it is the opposite. Dick is the one carrying around a dead corpse in Bludhaven which would have zero chance at lasting if not for Dick.
Seeley spent a long time and put a lot of effort into trying to build Bludhaven into something. He was also the perfect person to do this because he did not like the Dixon era Bludhaven and Blockbuster. He wasn't a fan of them and only agreed to write the book if he could do what he wanted in it. So he really tried to redesign Bludhaven to be something more than a "gritter Gotham" and tried give Blockbuster an actual character beyond a Kingpin knockoff. I think Seeley did as good a job as anyone could have and approached it the best way possible, but it didn't matter because it really showed the core problems of Bludhaven.
It ended up not working because at its core Bludhaven just is a bad concept and has very limited story potiental. There is just nothing there. It doesn't matter if they make it look live Vegas or a darker Gotham. There is just nothing in the city that inspires any lasting interest because it is so devoid of interesting elements. There is also no reason for Dick to even be in Bludhaven other than DC wants to make Nightwing their Daredevil and he needed to be in a city running around on rooftops and doing some boring normal job during the day.
Even Seeley understood why Dick had zero reason to go to or stay in Bludhaven so he just had him go to Bludhaven because Superman told him to go there, and tried to build him a love interest tied to the city to give him a reason to care about it and stay. Then he also tried to build up a deep connection between Blockbuster and Bludhaven that would again tie Dick indirectly more to the city. As DC wants Blockbuster to be Dick's archenemy (which is dumb), but again like with the love interest in Shawn it is trying to build an indirect connection to the city rather than a direct one because unless you retcon Dick's history a lot he has no direct connection or reason to give that much of a shit about Bludhaven. Then once the Shawn relationship was finished and Blockbuster was dealt with the city had to stand on its own and predictably it failed because it has no identity or anything that makes it special or any big ties to Dick.
I'll forever be bitter that the Grayson ended prematurely. That Spy Wars arc was probably going to be the biggest single story that Dick had ever been involved in that was HIS story that HIS own book was doing instead of being tied in to something the Batman book or the JL or some event book was doing, and it was all abandoned. I would have still hated Bludhvaen regardless, but it is was such a massive step down going from a story where Dick felt important to just generic street level stuff. I know Seeley tried to alternate between the Bludhvaen and world traveling stories, but I don't think that worked. It never felt smooth.