I understand your annoyance. Many use these words to say that some games or gamers aren't worthy of being called "hardcore" or true games/gamers. I hate that.
For me, casual/hardcore only makes sense when talking about the way people play games, meaning that any game could be casual or hardcore depending on how you play it.

Mr Khan knows what he is talking about.

What about casualcore?

There will be both.

That's what we call those casual gamers who have begun to play hardcore games but because of their past history of casual gaming can't be considered hardcore by the gaming Gods.

It stems from a desire to subcategorise users of gaming consoles according to their preferred gaming genre for marketing purposes.

Casual gamers are those to whom the gaming companies can market Singstar, Wii Fit, Lips, Buzz, Brain Training and the like. And there isn't much point in trying to market Madworld, Killzone, or L4D.

[Hard]core gamers are those to whom marketing Madworld, KZ2, and L4D bears the most fruit, and Singstar, Lips, Wii Fit and Buzz can also pick up sales.

The marketing types need to know who fits into what demographic so they can target the advertising accordingly: Use Olivia Newton-John to advertise Brain Training because that game will have appeal to 50+ year old women; don't use Olivia Newton-John to advertise Halo ODST because no one who would be interested in that game will have a clue who that old lady is, and she makes them feel a bit awkward for being sexually attracted to someone who is as old as Mum/Grandma.

Y'see [hard]core/casual is really iomportant from a marketing perspective and in the right context using these terms is useful. Even pn websites like this.

Is it untrue that there is a larger proportion of the Wii/DS market that marketing departments would categorise as casuals compared to the PS3/PSP and 360? The cunning thing for Wii/DS is that the casuals usually come bundled with a hardcore or potential hardcore gamer.

OTOH every type of gamer likes some casual games, whereas hardcore games only appeal to certain gamers. So games and gamers could be more neutrally described as mass and niche. But this isn't an exact correlation to casual and core, because there are casuals that are niche and core that have mass appeal.

Note the hardcore games I use as examples are there for the purposes of contrast, there is no suggestion that games have to be in the R / M rating category to be considered core, because it's pretty well recognised that Madden / Fifa / GT / Forza are all hardcore.

I use core (meaning established first party series that sell hardware, for example: mario, ratchet and clank). Some core games have moved out into multi-plat territory, thus losing their 'core' status.

As far as casual and hardcore, I prefer to instead use genre to talk about games. For example: FPS and racing games are harder to find on the Wii, its noticeable. What racing and FPS games are on the Wii are on rails (another 'term' but most understand what it means). There's no need to call Wii games casual or HD games hardcore.