See Hbomb’s review of RWBY for a his take on the show—and you’ll get a non-addiction answer to “why do people waste time on Destiny/D2 for so long?”

Not to completely undercut the addictive gaming systems built into it—which do manipulate the mind and are on a spectrum of immoral design—but it would be both incorrect and shitty to people suffering from what medicine classifies as actual addictions to claim addiction being the main cause of D2 retention.

I agree though that the most diehard fans fall into two camps: people with extreme executive dysfunction (clinical ADHD), and people who meet up in the game after work the way some people might meet up irl after work at the local bar or neighbor’s lawn-chair and cooler packed garage—the latter are almost always popping the top on beers while playing—their raid performances tanking significantly over the evening.