I think the whole debate about DPR is a big red herring. At the end of the day, MM is now a very different beast to almost all other attack powers.
Trying to compare the old with the new solely on the basis of damage output is like trying to compare a car to a motorbike and saying a motorbike is better because its faster! What about passenger capacity, all whether capability, the ability to tow. There are many factors in a deciding which is best.
To say "Its not as good because it doesnt do as much damage" (whether true or false) is just an incorrect way to assess the change. It ignores the utility auto-hit brings to the power.
To me, at the end of the day, its the preference of the user. Im not convinced MM is in any way an inferior power now, but I am convinced its different.
Ok, well what about people who are reporting that in addition to doing less damage, it no longer works properly with a good amount of gear and feats and other build options that the old one did, that in play it is boring to use as its a declaration only without any other part for the wizard player to play, or that auto hit flies in the face of initial 4E design goals that made all attacks roll to hit? There have been many more complaints than simply damage output being lower.