>>723505167
The "Scout meta" is glaringly apparent to anyone who simply plays the game. You're graded based on how fast you complete a mission, enemy reinforcements are infinite so you eventually have to rush a base anyway, Scouts get there quickest, and from there you think why not skip all the fighting in the middle since it's pointless.
Using Scouts to rush bases is the natural, logical solution to what the game is asking you to do.