The problem with making "low level" dungeons random is - it will destroy those newbies and low level players who are still learning the ropes and the mechanics. The better way would be to give high level rewards and make it as a daily they can do, that is worthwhile of their time, maybe 2-3 times a day at most. This will give options for people to do other stuffs than endgame, but still get similar amount of rewards. Also it gives others who try to pay it forward, a nice bonus incentives. Sure, you will still have to deal with trolls, but those despicable scum of the earth populates any type of games, and this is why "vote to kick/dismiss" is implemented.