Casual to me is someone who participates in end game content but does so at a level under performing of someone who's more hardcore. E.g. someone who expects to get a seat in a raid mon-tues that can't play wed, thur, fri when the FC's raid times are mon-sat 8pm to 12am eastern time. Casual might also refer to someone who tries to do titan but can't handle the amount of people failing on it and gets frustrated and requests a nerf.

Really a casual player is someone who rolls through content in a game and just wants to have fun and doesn't want to do a lot of work (not fun) to experience the content. They buckle first when something is hard. They are more likely to leave groups after 10's of wipes due to some elitism rage from someone else. They are overall more skiddish in feedback and don't handle criticism well and are emotionally driven. They don't except advice from others if the advice is not being given in a positive manner.

So they are casual: Not putting as much effort into something; Requesting things be brought down to their level; Complaining about elitism from the more hardcore players (who are are equally as frustrated in the opposite direction); Complaing something takes to long; Requesting bans against legit players that just want people to try harder and have run out of ways to positively communicate that;

I get that some people don't have a crap ton of time to play the game. IF so, join a casual FC with raid times that fit your schedule, don't try to join the servers best progression FC with 30 hours+ of mandatory raid time every week. And then don't complain about the content being the way it is because said FC won't take you and you feel like your missing out, that get's you labeled as casual.

People just need to accept that this is an MMO and an MMO requires more time from a player than any other game genre. If you don't have the time, maybe consider playing something that's not an MMO.