Sure, they can be wrong about that, but up till that point their feeling is that they hate them. Hatred is not necessarily a permanent state.
Incidentally, I neither bungled anything, nor am I playing word games, nor have I been "trained in philosophy". I thought most people knew that hatred is an emotion, that emotions can be based on subjective perception and that perceptions can change over time.
"I hate vegetables" doesn't mean "I am seething mad at vegetables right now." As for my other comment, it was a cheap shot but I couldn't resist. Sorry :).
Indeed, "Hatred" doesn't meaning seething mad. It means "a feeling of intense dislike; enmity"; if you "hate" vegetables it doesn't mean you are angry at them but rather at that point in time you have an intense dislike of them. Note that at a later date this can change to enmity's polar opposite, love.
The point being, is that hate is a subjective emotion, often based on perceptions that are not fully informed. To hate something you don't need to fully understand or know everything about the subject of the hatred. Witness Hitler and the Jews (I feel that this is an appropriate metaphor to allow someone to invoke Godwin's law so I can stop talking hatred towards innocent vegetables!)
The point is that to me, there is a difference between "I hate my boss" and "I hate vegetables." If I go out drinking with my boss and determine he's not that bad, I might express that as "I don't hate him anymore." If I try several new kinds of vegetables and determine that I like them, I wouldn't say "I no longer hate them" but rather "I was wrong - there are some I like."
This is because "I hate vegetables" doesn't mean I'm feeling something in the same way "I hate my boss" does. Again, what it really means is "if I eat a vegetable, I will not enjoy it."
Incidentally, I neither bungled anything, nor am I playing word games, nor have I been "trained in philosophy". I thought most people knew that hatred is an emotion, that emotions can be based on subjective perception and that perceptions can change over time.