Wasn't "Michael killing randos for 90 minutes" the plot of pretty much every Halloween movie since the original (and H3, of course)?
What would have helped the payoff in Halloween Ends would have been if they had planned out an actual story arc (beginning, middle, end) that would have supported...
True, although there are Silver Shamrock masks in the background throughout this new trilogy, so maybe, in this alt-universe re-quel, H3 is part of the MM canon?
Given that the entire ad campaign was built around an epic mano y mano between Laurie Strode and Michael Myers, it seems reasonable for the audience to expect said battle royale to occupy more than 10 minutes of screen time.