Why perverse? Who decided we are all obliged to live the maximum number of days possible? Why isn't it shallow to pretend death doesn't exist until you're forced to deal with it? As for friends and family, Manley didn't leave behind any children or people who needed him. Those who knew him are welcome (and in many cases personally invited) to read his detailed explanation. He could not have been more respectful.
You make it sound like because he had an apparently good life, that somehow gives him a debt he could only pay off by living as long as possible. Other people had shittier lives, sure, and other people had better lives. His life was his alone, though, and it's not for any of us to judge how he chose to end it.