If I say a dish is tasty I am describing a particular property of how I perceive eating it, not an intrinsic property of the dish itself. While the taste of a dish certainly depends on the properties of the dish itself we are all aware of it depending also on properties of the taster and that these properties are not equal for all people. Therefore we define tasting good in a purely subjective fashion – the definition relates not to intrinsic properties of the dish but to the individual’s experience of eating it.
Proclaiming, say, cheese to be good in itself is pure nonsense: how can an object contain a property of personal perception in itself! Good in itself can make sense only if Good does not depend on personal perception.
The obvious question is what should be meant by good? – but a more worthwhile question to ask at this point is why is good something we care about; why is good better than bad? Most would be inclined to think that it is obvious why good is desirable, that it is desirable because it is good. Commonly this is true because by good we are usually describing not an intrinsic property of an object but a positive perception of it, like cheese tasting good. Or call it good because it has an effect that we perceive as good, like a food product being healthy. Health is not desirable because it is good, we call it good because we find it desirable. If I do not find something desirable, why should I care if you call it good or bad?
To care about and to want are subjective, personal experiences, which we have already decided good cannot depend on. Good in itself can therefore not be said to be something we should care about. Indeed, saying one should care about something makes as much impact as saying one should like cheese. Perceptions are not freely commanded – and besides, why should I care about what you say I should?