Scout rifles don't do the damage to kill thorn users, and they have to poke in and out of cover because of the damage over time. As for there not being good enough sights, you can hit a headshot across first light with thorn easier than you can with a scout rifle.
English
-
I'm in favour of saying that MIDA's unique version of what I believe to be Ranged Lens RLS3 is the best scope in the game, whilst RedDot-OAS, -OES and Truesight IS are all fantastic scopes, the former 2 allowing higher target acquisition and stability, the latter providing acquisition and a clear, open sight for open scenarios. If you're good with a Scout Rifle and can land 3/4 headshots repeatedly, you're probably a better player than the average Thorn user and have a decent chance of winning at mid-range, dramatically increased if you get the first shot.
-