Of course... It worked this way in TBC and part of WLK and guess what... 12mln subscribers. Right now raiding is not that rewarding except for title/gear (which still looks the same as LFR/Flex [ingenious invention] counterparts) you are just another person who simply spends more time to see same content.
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There are people who can play Angry Birds for 20h a week. 1,5h per day is really little. Also it's not time you spend in game, it's dedication. I knew hardcore raiders who logged in only during raid time. They had shitloads of pots, flasks, buffs etc. in their banks thanks to earning with AH. Are they casual for playing 7 or 8h a week? Don't think so.