That second paragraph there from Frances Wright is in my view a good argument for why treating "Absence of pain" as the prime directive has to be explained very carefully.
I know from the moment I first shake hands with a new friend that he may well die before I do, and the closer we get the more the mental pain of his loss will hurt. The only way to avoid that will be for me to die first, which is hardly a more attractive alternative.
BUT I PURSUE THAT FRIENDSHIP ANYWAY because my goal in life is the greatest happiness through pleasure possible for me, not the avoidance of each and every and all pain.
I gladly and willingly accept the cost in pain that will be exacted in exchange for that pleasure, which greatly outweighs the pain.