Basically they pulled skewed and cherry picked metrics showing extremely low Linux activity to justify locking those players out of playing their game. It's scummy and their "trust me bro" attitude towards vanguard should be concerning more than anything.
What I took away from this article was that there's a shit load of cheaters in LoL, 15% of ranked matches or something like that had cheaters or smurfs. 1 in 10 games in NA and 1 in 5 matches in Europe is just insane.