i think this opinion is simply wrong. a lot of people do kill themselves out of a feeling of hopelessness. and yes, for some death seems very appealing at some point especially given a painless method. every time i read something by dfw i get the impression that he was just a little bit too infatuated with his eloquence and putting style over substance.
You are overindexing on the word "hopelessness", which isn't even defined.
Are you claiming that a lot of people are attracted to their death more than repulsed from their life, or (as DFW wrote) that they recognize death as the best option?
Outside of a religious death cult with ideas of heaven, I don't see people with painless lives attracted to death.