Most players who don't have the time can have more content to look forward to. Such as " Today I'm gonna play and try to kill <some name of a nm/hnm>.", or maybe the LS the the casual game is in can get a scheduled date to have the LS help him for a hour or so. Generally LS members are helpful, no matter the cost, and if you don't get to kill the NM or you do kill the NM but the item doesn't drop, so what. I can be a casual gamer at times due to IRL shenanigans and I would just try again. There will be so much content out there that it wouldn't matter if you had the time to kill a HNM that didn't re-spawn every hour at ToD. All I am trying to get across is, it's not excluding.. just more than likely giving you something to look forward to.