Low quality materials are not supposed to be completely trash, concentrate amount of them for better ones is common in lots of games with crafting system. For example, you take 5000 SCU of 0 quality iron (maybe purchased from outposts, or just bad luck) to refinery, pay a fee and wait for couple of days and you get 1 SCU iron with 500 quality. There could be a limit for this (like up to 500 quality), so ppl would still go exploring, mining (or pv...... stuff) for best materials (up to 1000 quality).