Quote Originally Posted by CaedemSanguis View Post
"level of investment"

even if the goal is to have fun, casual actually invest way more time than a good semiHC/HC group
Investment doesn't mean time. A casual group will be more invested in the group than the content regardless of how much total time they spend progging the content. A hardcore group will be more invested in clearing the content than the players and may kick players for poor performance if it helps them clear faster, etc.