I was chatting recently with a reader about WoW when he made a good remark: "The further you go, the harder it is to progress". That pretty much sums up the whole character progression game from level 1 to full T6 epic gear. It includes my wife complaining how slow it is while she approaches the level cap for the first time in 3 years of WoW. And it includes much of the whole raiding discussion on this blog.
From a game design point of view, that kind of exponential increase of difficulty with progress makes a lot of sense. Instead of having a linear progression ending at a hard wall, a "game over" screen, you get a MMORPG that appears endless, because the closer you get to the end, the slower you progress, asymptotically, so you never actually get there. Given the fact that developers can't create content as fast as players can consume it, this method is the only way to keep the illusion of endless progress up.
The disadvantage is that everyone gets stuck on that progression curve at some point, but all on different points. It becomes difficult to discuss where you are stuck, or to advise people how to progress further. Just as example, there was a recent discussion going on in some thread of how important it was to spend a thousand gold or more to gem up and enchant your blue gear to be able to progress further into heroics and raids. For somebody playing a lot, a thousand gold is probably a reasonable amount to spend towards progress at that point. But a lot of players who are more casual, or on alts, find a thousand gold to be a hurdle as difficult to overcome as beating a heroic or getting into a raid.
Matters are further complicated by the fact that there are more than one path of progress, all with different difficulties, often changing with time, and sometimes not equally valid for every character class. Sometimes you can overcome a hurdle on one path by switching to another and progressing there, like when you get some PvP reward epics to progress in heroics or raids. But that isn't an universal recipe, other players might be better off to be helped by their guilds through Karazhan, or to grind materials for crafted gear. You need to know a lot about someone to be able to give him proper advice on what to do when he is stuck.
The most fundamental change to those exponential progress paths are the expansions, which completely reset it. The day before the expansion is released you were stuck somewhere and felt you couldn't progress any more with effort that was acceptable to you. The next day you're back on easy street, with 10 levels of fast progress ahead of you. And as much as that fast progress feels good after having been stuck, it also makes you question your previous progress. Why did you spend so much time getting that one epic item at the level cap, only to replace it with a green random drop in the new expansion?
Therefore it is important to overcome the illusion of progress and achievement, and to concentrate on the fun you have playing. Goals are important as check boxes, as temporary objectives. There is nothing wrong in wanting a specific piece of gear, or a specific level of equipment which opens up new content to you. It is fun to pursue some goal, and to clap yourself on the shoulder once you achieved it. But progress by itself in MMORPGs isn't real, and if going further becomes too hard for you, doing something else is totally viable. If you ditch your friends and guild just for the promise of more progress in another guild, you'll risk finding yourself at the start of the next expansion with just hollow progress and no friends, and burned out from the effort it took you. Maximizing fun is a better strategy than maximizing progress.