It's definitely not the wrong decision, but this narrative that Dario is the big bad in all this when there are bound to be many, many more still within the game who knew and did as much has most certainly played its part.
There may indeed be more implicated. I'd be surprised if there wasn't. However the focus on Gradi results from the fact that he is a) high profile; b) currently involved in football, and c) concretely implicated by testimonial that has gone public. I cant think of anyone else who ticks all those boxes, hence the focus so far on Gradi alone (excluding those already convicted).