Your preferences are what they are.

Preferences change: sexual development is an obvious example. Preferences can be changed: "cultivating a taste" is a thing. Although in line with my original question, the only stock phrase I can think of that comes close to the opposite of "cultivating a taste" is "overcoming temptation". A taste, once acquired, is seen as something that can only be suppressed by a continuing effort, never removed.

An alternative approach might be described as "enlightening one's self-interest": learning to perceive the harm of something clearly enough that one is no longer inclined to indulge it.