Wanting a system like this would be a step beyond wanting to efficiently use your own time (you can already do this via PF and friends), and steps firmly into the realm of actively wishing harm to an entire segment of the community's time and enjoyment.
You can see how that may be viewed as... problematic, to some people.
Edit: The discussion of what's included in EX Roulette is another thing that must be kept in mind. There will probably always be 2 MSQ dungeons contained within it (Ala Mhigo and Skalla now, Skalla and 4.2's MSQ dungeon come Feb), and newbies would likely by default fall into the bronze category.