My defense points are mainly these 3 :
1. Yes natural Evolution developed desire and the fulfilling of it (Pleasure / Pain ) for preservation/reproduction. But that (preservation/reproduction are the intrinsic "goals" for our genes.
We are our self and ask for a happy life for our self (eudaimonia) not our genes (which we can give max. 50% further ).
2. Kastastematic Pleasure /Ataraxia/Tranquility : Regards eudaimonia and our value system.
We have no Tranquility when our values are disturbed and our values come from our desires.
Maybe this point could even divorce Epicureanism from other "hedonism" (comparing DeWitts "New Hedonism" in Epicureanism ) which often focus only on kinetic sensual pleasure of the "body".
- Someone has pleasure in feeling pain ? Isn´t it more the release of the pain ? And when it gets destructive an Epicurean would go over these pleasure for kastastematic Pleasure of health.
-Morally bad Pleasure ? => When it would destroy friendship or the justice to others it would destroy our values, securities, good feelings/pleasures with others, chances of reciprocy advantages, bring great disturbances and destroys our kastastematic Pleasure, so an Epicurean would avoid it. Nature gave us for that feelings like compassion, empathy and good feelings(Pleasure) by helping others.
3. Faculty of Pleasure/Pain vs. feeling Pleasure/Pain for things/situations
The faculty of Pleasure/Pain is to be secured (against tranquilizers if not necessary). We want Pain as the guide when we should avoid something and Pleasure when we should pursue something.
It is our navigation system, we should not change /reduce our feelings like the Stoics but navigate in our life for Pleasure / avoiding Pain by being sensible for our feelings.