I'd consider that casual when I only play about 10 hours a week. Casual shouldn't be used as an excuse for poor play nor should it be used as an insult. Casual is a word that lost a lot of its meaning. People forget that casual has to do with time investment. Bad players use the "I'm a casual" excuse to explain why they're bad at the game, despite playing more than many heroic raiders. Then the elitists (often LFR raiders who play toooooo much WoW) use it as a way to complain about the game on forums to look bigger and better than they really are (if I yell really loud and insult everyone, maybe people will ignore my achieves and I'll be a cool kid!")
Mists of Pandaria dailies for example did nothing for casuals. They made casual play harder as you spend what little time you have grinding out dailies for rep and valor instead of doing the fun stuff like dungeon crawling. If anything, Mists of Pandaria, despite having more end game content, caters more towards the "hardcore" players who can invest more time in a toon each week (much less multiple) than any game version since classic. Meanwhile, casual players are grinding dailies and have little time to actually play alts.