Screw variety.
I want to be able to chose which playfield I want my missions in. For those who wants that random thing, there could be a option for it.
Because that is the point, isn't it? People should be able to chose where to go themselves.
You don't have to change the system at all. The old one can be left as it is. Just add a new function that allows us to chose.
Then those who want close missions can do so, and those who wants them far away can do so, and those who just love being chased by a vulture in Agaean can do so. Then all this complaining will stop, because there will be no reason to complain.
Having assignments that are randomly given out to the 'man on the street' is just stupid.