Because the 6MOA dot of the Mepro21 is not good for shooting groups - no one wants to go shoot groups and report crappy results.
well, my results are crappy but at least its a good starting point. What is that you guys do on demo shoots? If you squeese the trigger it makes boom we all already know that.
Red dot required some homework like finding target with bull big enough to use at 100 yards. 8" bull leaves just about enough black around edges that I think if not for M21 it could be as accurate as peep sight. Paper plate might do just as good target by the way.
My 3-shot group measures 47mm which is under 2 MOA. 5-shot group at 50 yards is 26mm - you can see vertical spread attributed to parallax distortion. Considering sights I say Tavor is not 5MOA neither it is 3MOA gun. Well-tortured piece I had is more accurate than any brand new AR out of the box. Better than most tweaked M14's with fancy scopes on it.
I say if more folks did something like that we would have a little more ground for arguments. Post something, measurable groups are always good point. Good or bad - don't just BS.