There are better directors than Abrams with which to replace Snyder. However, Abrams would at least be a sure thing, as in a sure thing to produce an "adequate" justice league film. Most of Abrams' recent films are adequate, certainly better than adequate from a commercial standpoint.
But WB should really let go of Snyder at this point, or at least curtail him. The DCEU is rapidly becoming toxic, like Transformers and Twilight before it. If they keep it up, it will have the same reputation as Transformers and Twilight, where people all over the world can just say things like "The Superman movies are proof that box office and film quality are unrelated" or "The Superman movies show that if a dumb movie is pretty to look at, it will be fun for the masses".
Eventually that catches up and becomes toxic. Transformers 4 had a North American gross that was ~30% lower than that of Transformers 3 in spite of adding in the dinobots, and Transformers 5 is likely to do worse.
