Sadly thats not the case, its simply that a Season 3 of YL doesn't fit int eh scope of the DCU DTV project. the DCU DTV project is supposed to tread the water and try properties while trying to remain profitable. We see some very heavy attempts at that (IE Green Lantern: First Flight, Wonder Woman and The Flashpoint Paradox) but we also see some kneejerk recoils when movies fail to meet expectations and they need to firm up internal support.
Though a story set in Earth-16 might not be contrary to the DCU DTV project, doing a Season 3-ish release would.
Frankly, I think the series WAS profitable enough that DC should be able to justify another DC video release project grounded in Earth-16 with 2 movies a year based on Young Justice, 1 movie a year based on the Justice League of that universe and 1 movie a year based on a "Super Hero Family" (IE Bat Family, Super Family, Flash Family, Wonder Family, etc).
8 DTVs a year from DC should actually justify things and I think if they churring out DTVs almost monthly (and heck, I won't be opposed to DCU pumping out 6 and Earth-16 pumping out 6) then I think we PROBABLY would see a raise in sales. I do think part of the problem of sales is they aren't regular enough for non-regular fans to pay close enough attention. I think DC needs more releases, not less. More releases = more exposure.
And when season 1 was airing, he admitted that he'd been looking for ways to give Cap a role in the show.
