Are.. are you using your brain?
Not to be rude, since my opening statement clearly was.
What you're asking Riot to do is create a way in which to harshly punish EVERYONE for being slightly toxic? We ALL have those days where we're being overly angry and toxic, and getting one ban gives us a decent warning to smarten up.
Asking Riot to fuck EVERYONE over because of the faults of a few is ridiculous, and LOADS of cafes would lose business from players that purely went for League, and trust me, it's a LOT.
And in Dorms, or shared households you're basically fucking over the siblings that didn't do much wrong because one person went full retard.
This "Soft" IP ban will do nothing but drop Riot's customers, something they would rather not do.. at all.