I have a different theory; no one bothered about it because it wasnt shown directly. Kvyat was shown. Vettel moving into Kimi was shown. Kimi going off track was shown. 15 cars and 4 seconds later, Hamilton / Nasr was shown from Hamiltons camera. What isnt really visible from that angle was Kimi ahead but to the left of Nasr moving back on track.
I think Kimi was lucky that the stewards probably missed this. You can see it in the overheads though, but by the time Nasr / Hamilton happened, the focus was on the 'effect', not the 'cause'.
Wouldnt have made Hamiltons or Nasrs race any better, but i am fairly certain a dangerous (and avoidable) move like that should have been penalized on the grounds of how dangerous it is.