Well it appears that it's your problem not the game's one. You are free to rush through content but do not complain if you finish it too fast. Every cake finishes after all, if you gobble it up in 5 minutes there'snobody there to blame but you
On the bright side, in a month you're done and can move to other games without additional subscription fees so I don't see the problem here. Honestly, games that take an infinity of time to level up (see the old Lineage II at 1x) are terrible - the progress is so slow that the average player (me included) hardly ever sees the end game. That's bad as well.
I rushed the first level in the beta because I wanted to try various stuff and have a go at PVP but I didn't enyoy it. When the game comes out I will talke my time, what's the point otherwise. If you don't enjoy the content, it's a job, not a game