It sucks but that has to be the case with showrunners. Either you have a great one like Fuller/Esmail/etc., an OK one like Berlanti, or a crappy one.
Obviously shows are more than the showrunners, but from a network (and IP holder perspective), you either trust the showrunners or you don't. And HBO's whole thing is they let the creative team pretty much do what they want, and it usually works out because HBO usually has good judgment about which showrunners to trust. Sometimes it works out, sometimes it doesn't (True Detective s2 hey-oh.)