Thank you for a very well thought out post. I think I was thinking more about time per play session than overall time per week or month. I suppose they are still interrelated. It does change how I was thinking about the topic.
I agree that the term "casual" takes many shapes and forms. Personally, I don't feel that casual is only relegated to time. However, I do think that is how ANet defines the idea of a casual player and, therefore, I wanted to limit the definition just to time frame only for this discussion.
I generally define 'casual' as being resource restricted in a few of ways. (and this is more or less a breakdown of what Morghan was talking about)
Time, capacity to organize, capacity to learn, capacity to perform, capacity to optimize.
The first is easy. If you're falling below the curve to when people obtain a goal due to time constraints, that's definitively casual.
The second one occurs when you lack a persistent organized structure. No voice chat, pugging versus grouping with regular people, little if any willingness to communicate with people and make friends in a game. Very 'ronin' type of experience, where you might group up with people as they come along, but communication and organization are kept to an absolute minimum.
The third comes from a lack of ability or willingness to learn about the game itself. How each class functions. How your class functions. The type of thing that results in sub-optimal builds. Incorrect gear that does little or nothing for your particular profession or build. Not really knowing how the mechanics of the game work beyond your own observations and not reading up.
The fourth type comes a lack of ability to improve on a skill level. You may react properly. Everyone does, eventually. The whole 'not dying' thing is a good motivator there. But at that point, you're reacting to things and are rarely thinking very far ahead and really aren't trying to be even above-average in terms of skill.
The final type is the lack of drive to obtain the BiS gear, due to constraints in the game forcing you to violate the other four tenants. The cost is not worth the reward in this case. You don't want care enough to sink your time, you don't want to socialize, learn the game or pay it enough attention to be better than 'not dying.'
This doesn't just happen in RPGs, but other games as well.
Tribes: Ascend and the entire franchise were games based on physics weapons as opposed to hit-scan weapons. You not only had to control your travel through inertia-based skiing, but also most of your shots were affected by your speed, direction and so forth. It had a high skill ceiling and even taking a week of the game for me reduced my ability to play.
Same thing happens in DOTA2 and LoL and other shooters besides Tribes. You need to understand how the game works, you need to invest the time to play regularly, you need to organize with people regularly and have optimal builds in order to move beyond casual play.
In relation to Guild Wars 2, as noted in the now locked thread on 'Zerkers Only' the game is very
forgiving in some ways that makes not stacking damage mitigation gear (vit/tough/healing) better. However, its vertical progression and the way its done forcibly rips apart the casuals from the hardcore with a wide gulf in the middle.
The first problem is 'one path for all.' Interestingly enough, the whole concept of 'daily rewards' were designed to give people who could only play for a short amount of time money to keep up with the rest. The problem is, the daily rewards are the most profitable part of the game and once done, unless you've got the hardcore quintet, playing the game becomes a whole lot less rewarding after the fact.
As a side effect, the hardcore folks are throttled so they don't outstrip the casuals too quickly. Hence time-gated, account bound crafting materials.
The second problem is a the wide, yet shallow pool that are the game mechanics. Based on your weapon choice, it's going to probably dictate your build and gear layout. Despite the availability of skills, unless one skill swap is a serious game-changer on an encounter basis, that will also be dictated largely by your overall build. Despite having a broad variety of skills, weapon and utility, as well as traits, there's shallow optimization. Not to mention how some concepts are neutered to game mechanics like Defiant. Ultimately the problem here is that with such a wide pool, a lot of people are left stumbling trying to figure out how to be optimal and probably much like myself, the concept of 'cookie cutter' builds aren't that fun, but given the lack of depth, the optimal build for a particular weapon set has probably already been found and embraced by the community.
The third problem is the enemies. Massive health pools and one-hit KOs. Tanking in trinity games at least gave a measure of control over the fight. Now you have to just be ready if the One Hit KO guy decides to turn on you for no apparent reason, leaving control up in the air. The framework of the trinity let casuals know what their role was and not to screw up, in this regard. Here, they probably expect a Guardian or Warrior to be taking most of the hits if they're wearing a shield. Despite the mechanics tips, there's no real concept of what they do until you run through it. GW2 wiki is no wowpedia in this regard. And again, Defiant messing up people who are used to having some measure of control over a fight.
The lack of well-paced progression, the lack of an easily graspable combat system in which your choices have a clear effect on fights (and that gets lost in the massive health pool fights), and easy to grasp encounters makes the game a little casual unfriendly.