Check this, and CTRL+F “Recognize a smurf”. Sadly I can’t link you to the exact part (I should’ve reserved some posts at the start 
). If enough people are interested I may give my tricks to guess smurfs at the loading screen.
The reverse is more efficient, cheesing smurfs while being used to play macro. Anyway, the key point is to make tactical bets rather than mechanical ones.
That’s was what some of them present as a motivation, testing new things, strats, etc. Likely only part of the truth. You don’t need to lower yourself two leagues below to test builds.
The bulk of the population is at intermediate levels. Smurfs only aggravate that by going from their leagues to those.
As for the devs not doing anything, that’s probably more related to them not seeing the phenomenon as dangerous.