The reason people are getting sick of Nu's crap is because every time she shows up, Ragna's situation just gets worse and worse. And the dude already has everything else in the world to deal with. Not even Jin gives him as much crap as Nu does. Yea yea, sympathetic past, I get that. That doesn't really change what she's done mind you.
That said, the death scene was well done.
As for the anime as a whole...yea, it definitely would have benefited from being a 2-cour anime. That probably wasn't the case since the studio who made the anime are still relatively new and probably just couldn't afford it. Its sad, but understandable and now was the perfect time to produce an anime with it coinciding with the release of a new game.
Could it have been better? By a long shot, but for what it is, its decent at the very least and the studio worked with the material they were given. Yes, a lot of content and characters were severely shafted, but they at least changed things around for the characters it DID focus on.