You seem to fail at math. Or you're just so shortsighted that you don't even realize what you're saying. You do realize you can only do one set of leves every 36 hours, right?
Let's say you get 40k EXP out of a set of leves within one hour.
That's an IMMEDIATE 40k/hr of EXP, while grind parties can maybe get 30k/hr. Looking at it that way, it seems like leves are overshadowing EXP/hr by a large margin, which is what you seem to be whining about.
But you're overlooking the fact that you can only do one set of leves every 36 hours. So that changes the EFFECTIVE EXP/hr. The actual effective EXP/hr of one set of leves is 40,000/36, which equals about 1110 EXP/hr.
Add the fact that hardcore players can do leves every reset too, and the amount of EXP/hr for a casual is nothing in comparison.
The system is fine. You just need to get out more.