It is actually very true that it is possible to spend a great amount of time in this game without hitting 50. Sure some people focus exclusively on leveling one main class, but not everyone does. I spent at a best guess roughly 35 hours playing in the past week(Yikes that is a lot. I need to cut back clearly), most on the same character.
I ran dungeons a lot, I leveled crafting a little, I did a few quests. End result? 5 crafting classes leveled no more than 10 levels each, 1 Magic class leveled 2 levels, another magic class leveled 4 levels. One gathering class leveled 4 levels. Did I manage to level a single class to 50? No. I know if I had focused on one class I probably could have leveled say Archer from 20 to 30 or so, maybe 40.
So 1 to 50 in a week? Wow. I can't even imagine how much time that would take, 70 hours a week? I don't mean to be argumentative, I simply think you have an unfortunately misguided perspective of what the average much less "casual" players free time to play this game and general investment into the game is.
And that I think is where the rusher argument comes in.
This isn't to say there is anything wrong with that. If you are end-game focused I can certainly understand being frustrated with current limited grind based end-game content, but the fact of the matter is that a game like this has to do its best to cater to the majority of players, while still providing some level of content for the smaller percentage who have the time to focus that intently. If they focused exclusively on those who were end-game content ready quickly no matter what, there wouldn't be enough content for the slower paced majority, nor would they have the needed supplemental classes such as crafting and gathering which help sustain a long term economy.
So truthfully, I don't disapprove of your play style, but it is definitely going to be the one that has the hardest time this early on in game cycle just because developers have to focus on the overall content and environment suitable for gaining and sustaining a much larger player base in order to offset investment costs.
Not "white knighting" not name calling, and I am truly sorry this game is in a hard place for your preferred play style right now, but the fact of the matter is that yes, a month into the game, you are still in the minority here. My guess is it will be another 2 weeks before a large minority of players are end-game, a month for a small majority, maybe even 2. Hope you can find ways to enjoy the game in between your current end-game grind.
Personally I find it is quite satisfying to keep re-running the lower level dungeons I have long since mastered especially with new players, and can spend hours doing just that. My expectation is I will be alternating end-game dungeons with low level story and non-story dungeons, and trying out the other jobs at least until 2.1 comes out.