Keep in mind that in 4.0b and in the tournament, lucario had no aura. In the developement build he does, and it is pretty batshit crazy to be honest. Lucario in the tournament was very very fun to play as, and never once did i wish i had aura. In addition, aura makes the concept of set combos entirely impossible. Lucario is already volatile enough, and i don't believe he needs to be any more volatile mid stock. At the very most, i would like to see stock aura remain. Though i am just as happy not having it at all.
It is much much harder to completely rebalance and redesign lucario around aura again than it is to simply take the focus from it. I'd rather keep my set combos, and not kill people in 3 hits unless i work to get that setup. Not because im absurdly strong.