It is rather amusing how Vampire Barnabas had enough power over Willie in the early days to stop him from running away, ratting him out, or staking him while he slept, yet he never did much about Willie arguing with him. Perhaps he secretly enjoyed having someone to at least try to argue him down from the precipice of disaster?
If only Barn had actually listened to Willie (and Julia) and taken his (her) advice. But that would have required him to consider the possibility that an opinion other than his own could be valid.
And I don't know how much he enjoyed being argued with, considering that he often violently/physically lashed out when Willie (and Julia) disagreed with him. Though what he might have been enjoying was being provoked to physical violence because he seemed to love to threaten Willie and he certainly attempted to strangle Julia often enough.