How much information is complete information?

The Italian communications watch-dog Agcom has told Rai and commercial broadcasters to give more coverage of the campaign to call a referendum on the current electoral law. The instruction is binding, though any penalty could easily be evaded; but what possible (non-normative) justification can Agcom give for this? Let's say Agcom finds out that 5% of time of news bulletins has covered the referendum campaign. Is that a lot or a little? It presumably depends on how important one thinks the referendum campaign is. That seems to me to be a journalistic decision, not a regulatory one. Agcom should stop giving judgements of this type.