The bottom line answer is "because they chose to".

Whatever all reasons you want it this way or that way or think it's best on a Tuesday upside down with R0, it's because this is what they decided. Of course they could have done xyz to for q result, of course many people could suggest ways to balance it or that are often players who fail to do job quests or just fail to play their actual job, so "what about" "if this" - bottom line is they just chose not to.

;/