"Foolishness, Dante, foolishness. Might controls everything, and without strength, you cannot protect anything. Let alone yourself."
And this is where differences in opinion, thought, and interpretation can come to play. To me, when Vergil makes this statement, it simply comes off as him mocking Dante for wanting to use power for anything but destruction, let alone to protect anyone. Again, part of the cliche of villains wanting power for the sake of having it only ever want to use it for the sake of their own personal gain. Again, Vergil never gives an indication as to what he wants the power for.
If Vergil had really cared for their mother, and was remorseful for her death, you would think he would take into consideration the children and mothers of the city that Temen-ni-gru was underneath. By reviving that tower he set various demons lose upon to an unknowing populace. I often wonder how many mothers and children had been killed off screen as a result of his actions.
If Vergil had really wanted to attain power, for the sake of protecting others, he never would have put innocent lives at risk. Which is one of the primary reasons as to why I do not understand people wanting him to be some sort of Anti Hero, or some precious child who didn't know what he was doing. He knew damn well what he was doing, and he knew lives would be put at risk from his actions: and he simply didn't care.