Hey, network execs tend to run on cray cray logic. I wouldn't be surprised if they thought of the two shows as being redundant just because they both have teams with young membes, despite having drastically different tones. Besides that, Beware the Batman and Green Lantern will both be their serious shows, and if Young Justice has the weakest toy sales they can justify dropping it in favor of a comedy show that brings variety to the block. Also Young Justice isn't a shiny CG show, I'm sure the thought process would be "kids love that CG shit - guaranteed money! Kids won't go for serious cel animated cartoons anyways, 2D is for babies."