There are plenty of other producers and directors in Hollywood infinitely more talented than Ronald D. Moore and Bryan Singer. I suspect the reason why NBC-Universal / SyFy Channel has chosen not do to business with them is because they are all "A-List Talent" requiring a great deal of money to keep them within arms distance reach.
Ronald D. Moore and Bryan Singer on the other hand, are "Cheap-O B-List" affordable hired hands within arms distance reach of NBC-Universal / SyFy Channel eternally on call for the next rotten project NBC-Universal / SyFy Channel wants to make.
Even though Ronald D. Moore's sham take on "Battlestar Galactica" was not a commercial success, even though Bryan Singer can never get himself out of the embryonic, pre-production phase of making a "Battlestar Galactica" movie (after 11 years), the two of them are still attractive to NBC-Universal / SyFy Channel because they are alot cheaper to keep around as "hired hands in limbo" as opposed to trying to hire to the mega-expensive status of Joss Whedon.
It would never occur to NBC-Universal / SyFy Channel to hire anyone other than Ronald D. Moore or Bryan Singer to dabble in "Battlestar Galactica" because everyone else in Hollywood has talent and is too expensive for NBC-Universal / SyFy Channel to hire. Which is why, for example, Bryan Singer still..."kinda, sorta"...still hangs around NBC-Universal / SyFy Channel after not producing a "Battlestar Galactica" movie for them after 11 years. He's cheap and affordable to "kinda, sorta" keep around.