These quests are made for the avid miner that I am. The quest probably has a exp bonus for completion based on the time that it takes to complete. Most games do anyway.
Also since you get a bonus exp per roid or gas cloud that you mine and a bigger bonus for the field 100 ore really isn't that bad. You'll stock upon mats, make money, and lots of explore exp. And the game is about having fun. If you don't like mining, try some other missions.
Ray out~