This is an honest question because I'm starting to wonder if the higher ups at WB actually know what to do with the character or worse still, if they are indeed fans of the character. (I'm not saying that WB ACTUALLY HAVE a problem, just wondering aloud). A broad look at the movies and how WB seem to "dump" Superman after re-launching the character is actually troubling.
After Donner left, we got two very,very horrible Superman movies -Superman 3 (i think Richard Pryor even had more screen time than Superman in this) and Superman 4 (Superman 4 wasn't WB so we can't blame them). Superman Lives was then mooted and developed up to a point but eventually fell apart (as an aside, this movie actually sounded quite interesting after watching the "Death of Superman Lives" documentary"). We then got false starts with Brett "The Predator" Ratner and McG until Singer came up with a version that continued the Donnerverse. At this point, it was clear that WB wasn't comfortable with anything Superman outside of Donner's version. Superman Returns was released and continued the Donner version, Bryan Singer was a good choice on paper but what he made was dull as dishwater and while critics liked it, fans haaaaated it. Superman Returns was not a flop and there was still a possibility of building on this but sequel plans were never developed (which was odd because Batman Begins didn't do spectacularly well but still got a sequel). Superman went dormant again until Zach Snyder came along and gave us Man of Steel which frankly was far superior to all the previous Superman sequels but divided fans and critics alike. Man of Steel re-booted the character and made good money (it wasn't a massive hit but it did well enough) but for some reason, WB simply moved away from a sequel and then we got BvS (i'm not going to go into that, everything that needed to be said about BvS has been said).
Now, we are hearing that WB is developing a Supergirl movie and considered Michael "Killmonger" Jordan as a potential Superman (which all likelihood will not be Clark Kent because of the dynamics of Superman's origin regarding his human identity) and there are no Superman plans for years; to me, this looks like WB giving up on Superman in his most noticeable form and are moving onto something else. Since Donner left, it seems no one has been able to present a working version of the character that WB is actually comfortable with and beyond that have no real interest in producing Superman movies. BvS and JL weren't well received but they are still going full steam ahead with a Batman movie but Superman gets the shaft...why??"