Because we're talking about a failed studio which has been strugling to develop a properly cinematic universe during 16 years, and keep insisting in waste time and resources on things that aren't going anywhere.
James Gunn himself know this. He cancelled The Autorithy movie, Waller TV show, Paradise Lost TV show, Swap Thing movie, Sgt Rock movie. Most of his own nonsense projects got cancelled and he appealed for announce a Superman 2 movie which we're seeing it will be a JL movie disguised because he aknowledge his mistake. That's how things work, dog.