Because plastic prepainted miniatures look like junk. Yeah, hey, a fighter with a sword that's bent into a "U" that I can't unbend? Yeah give me more of those!
Because plastic prepainted minis are nearly impossible to strip and repaint - at least ddm minis are. I threw simple green at them, alcohol, and my editor used oven cleaner. Nothing doing.
Because all Hasborg needs to do is twitch their little finger and change marketing tactics slightly and suddenly Reaper is stuck with a bunch of miniatures and a manufacturing process that they can't get rid of. When the LEGEND OF FIVE RINGS license went away, or the EXALTED license went away, big deal! They had a few metal molds in Texas they didn't need to use any more. If Reaper is "successful" and does pull a significant number of DDM fans away, a slight adjustment by the multibillion-dollar megacorp behind WotC is all that's required to put an end to the argument ("Sell them non-random, get these guys off our backs.") and suddenly Reaper's audience leaves. If Reaper is unsuccessful? Then they've shot themselves in the foot at the word "go".
It WILL detract from the metal minis. How can spending the bank on a new manufacturing and painting process not detract from metal minis? The money that would have (should have) been spent on the metal minis side of the house is now being put into plastic prepaints. I don't buy it for a second that this won't negatively impact the alloy minis. Not one second.
I see this beginning the end of either the Dark Heaven "RPG" line of minis. Maybe not now, and of course Reaper won't spin it that way. They'll pitch it that if you want a highly detailed character mini, buy one of their wonderful WarLord minis. If you want bulk monsters, then buy the pre-painted plastic ones!
This is just...I just can't see any good coming out of this whatsoever, I'm sorry.