When she says that it's almost always in frustration in response to something he did and shouldn't be taken literally.

Their relationship is complicated and broken but they're still father and daughter and the love between them still exists. Maka wants her father back but can't accept his behavior. Spirit wants to repair their relationship, but is unwilling or unable to modify his behavior to do so. Which makes him a flawed human being and a shitty father. But he's not a monster. Just kind of an ass.