I dunno about ended well, but it definitely ended lol. The story of LR is pretty bad imo, at least as a sequel. I think the original XIII had a perfect ending and left nothing unresolved, so I like to think of the sequels as their own canon. I mean, they're so insane and off the wall they're practically their own separate things and just act like sequels so that they can reuse assets and characters.
Personally, at this point, I'd be much more interested in remastered versions of the XIII games, in particular the first one. I agree that the series should die with Lightning Returns, attempting to make a sequel to that mess would surely result in a trainwreck of a story, if you don't already consider it one, anyways.
EDIT: Actually, now that I think about it, a prequel or simply some sort of other story taking place in the original XIII universe could be really cool. But enough of the original characters, please.