It's a term that doesn't really mean anything because everyone views it differently. When I used to play WoW I was happy to be a "casual" because a lot of people there considered anyone with a relationship/spouse, social life, etc. a "casual." This was due to "hardcore" being all about raid progression and being consistent to a weekly raiding schedule that many "normal" people couldn't adhere to. But casual isn't always the same as incompetent, that's a strange mischaracterization. In WoW I played casually but I had a lot of friends in the top raiding guilds and would get invites to raid pretty often because I was considered one of the best healers on the server. I have no idea what "Casual" is supposed to mean in Destiny though. I think I'd still consider myself fairly casual because I don't take the game seriously, but I have done the raid (legit too, not cheating), and I have solo'd the nightfall strikes several times (okay that was done with cheating). I don think the game is old enough and there isn't yet enough content to really parse what makes one a casual or not. :P