Learn English – what can be the antonyms of “motivation”

A nice word could be:

Prospective

As in:

"Being a manager of this branch is prospective indeed."

Word pairs like love and hate, right and wrong are gradable antonyms:

A gradable antonym is one of a pair of words with opposite meanings where the two meanings lie on a continuous spectrum. Temperature is such a continuous spectrum so hot and cold, two meanings on opposite ends of the spectrum, are gradable antonyms. Other examples include: heavy, light; fat, skinny; dark, light; young, old; early, late; empty, full; dull, interesting.

The words you're looking for are midway along the spectrum between gradable antonyms, so medionym would be a good neologism. However, there's another way of looking at this.

Love (in the sense of passion or ambition) is also the opposite of indifference – just in a different direction from the love–hate spectrum. Likewise for right and ambiguous. The words you're talking about are still antonyms, of a special sort that is opposite to both ends of a spectrum. A good name for this would be orthogonal antonym, to reflect that it is “perpendicular” to gradable antonyms.