You've provided data for my assertion that the big, establishment players oppose flash orders. Of course the NYSE opposes flash orders. The NYSE is the big, old, fat cat. The ETNs where flash ordering is common are small upstarts that offer lower transaction fees and better technology.
The NYSE's members are the big market making firms who have the most to lose if there is more competition -- IE more small firms using market making strategies.
The NYSE's members are the big market making firms who have the most to lose if there is more competition -- IE more small firms using market making strategies.