An article at Gamespy really hit home the difference between two large categories of MMOG players, as Leif Johnson describes the expectation in end-game style MMOGs that players will use third-party MODs that basically automate increases in raid and dungeon efficiency. Leif describes how, even though his group was having no problem clearing content, simply clearing the content wasn't enough for their tank when his MOD showed that one of their DPS members wasn't doing as was "normal" - or "expected" (expected by comparison to websites that show averages of DPS). The tank left the group because the group wouldn't vote to kick out the sub-par DPS contributor.
These MODS are generally aimed at doing one thing: making the game play more efficient by providing tactical and logistical support, information, and automation. Basically, these comparative numbers and game-data (maps, mob locations, movement and instructions, gear comparisons, dps, tanking and healing comparisons, etc.) turn players into little more than min-max automatons, and have gradually organized how they see games into terms of numbers, statistics, and efficiency. Thus, an entire online world becomes nothing more than a mathematical construct and their characters nothing more, really, than a limited variable seeking to shape itself into the most efficient formula to best fulfll an equation.
Unfortunately for game developers, this min-max mentality trivializes 95% of their efforts. For many of these players, it doesn't really matter what exists in game world outside of the game numbers; if it doesn't add to their level/power/play efficiency towards maximum forumula resolution (character power), then it is unnecessary "fluff". Under this view, character "balance" essentially means that every character is a mathematical variable that, when played to maximum efficiency, has the exact same formula resolution capacity as any other character.
This is how many people view MMOG "Game Play". Now I have a better understanding of what I mean when I use the term "Hardcore": it is the player perspective that sees the game in terms of a mathematical formula, and one's character as a variable by which one is attempting to "solve" the formula as efficiently as possible. They generally use whatever means are available to do so, including mods and information off of various websites. For them, solving the mathematical "problem" any game represents (min-maxing) is what "Game Play" is.
Casual players (as I'm defining them here), on the other hand (and IMO), generally do not see the game in those terms; they see it as a "World Experience". Casual players are not trying to "solve" the game, or "beat" the game, because they don't really see it as a "game" in any traditional sense, but as an "activity", more like a hobby. They see MMOGs as ANET describes GW2 in their latest ad trailer: "a deeply-customizable role-playing experience." Casual players generally don't use mods or scour the internet for information to make their play more efficient, but rather only to get through particularly frustrating content (like a particularly baffling jumping puzzle, or the location of a particularly elusive crafting material).
The hardcore (mathematical, min-max) mentality has dominated the MMOG genre for almost a decade now. This has created an infrastructure of terms, definitions and expectations that glorify the min-max mentality, and belittle the world-experiencer mentality. For example, the term "zerg" is used to denigrate any game encounter that doesn't require min-max, formulaic efficiencies on the part of each player involved. Included in these "efficiency expectations" are things like: standing in X spot, avoiding X when it occurs, supplying X dps, supplying X tanking, X healing, X crowd-control, etc. If the encounter cannot be reduced to min-max formulas of necessary character (variable) input, then it is a "zerg". If a player is not up to gear or class role min-max expectations, they are "bad" players or "scrubs", and are not invited to raids and are kicked out of groups. "Class Balance" is an expectation of the min-max crowd, and a game is not good unless the classes are "Balanced". "End-Game" is a term and aspect of the game reserved for those that have mastered the mathematical formula, have maximized their power and minimized their encounter time expense and use their characters as nothing more, really, than highly efficient variables in a formula.
IOW, if you don't play the mathematical game, you are a bad player, and basically locked out of seeing the top, end-game content, because game mechanics (and the resulting kind of community it generates) requires min-max, hardcore gameplay. If you are a casual player - a "world experiencer" - then you basically had to settle for scraps in virtually every MMOG until GW2, because your non-mathematical, non-min-maxing playstyle could only get you "so far", and no further. Games that do not challenge and reward the min-max mentality are "boring" and without "motivation" or "proper risk vs reward".
GW2 has provided a real home for the "World Experiencer", but the Game Players are a very vocal and pernicious bunch. It's not that there isn't content for them in GW2; there just isn't the slavish devotion to them in GW2 as there is in most every other MMOG on the market. As it is today, Tyria is a world that treats the "World Experiencer" (casual) as an equal to the "Game Player" (hardcore), and the basic structure of the world system supports this. One doesn't get uniquely rewarded with superior content through a min-maxing playing mentality. Players can get top-quality content via the "World Experiencer" playstyle, so GW2 is a true alternative - and basically, the only available alternative - to what dominates the current MMOG marketplace.
I hope ANET stays true to this vision. It would be a shame if a vocal minority succeeds in turning GW2 into another min-max love-fest that caters to hardcore players by providing them with functionally superior rewards for their playstyle.