It's up to the airline to press for prosecution.
Not disputed, but the airline can only
press for a police prosecution. If however, the police/DPP decide against proceeding, then the only litigative option for the airline is pursuance of a private prosecution. As will be appreciated, that wouldn't generally be recommended for a variety of reasons.
Having said that, perhaps the airlines could be a little more generous about adding disruptive pax names to "No Fly" lists, and circulating such amongst themselves. Although would that in itself, without any previous supporting guilty verdict in a court, then lead to claims of "discrimination" against the airline concerned?