The state almost always wants to make a plea deal in criminal cases, since trials are really time-consuming and expensive. IIRC, upwards of 90 percent of US criminal convictions arise from guilty pleas for this reason. Typically, accused criminals are much less powerful than the prosecuting attorney’s office, so the state more or less gets to set the terms of the plea bargain. (This isn’t really a good thing!) But when the accused criminal has hundreds of millions of dollars, and access to high-powered lawyers like Dershowitz and Starr, then he has a lot more power to set the terms. No prosecuting attorney wants to be on the wrong side of an acquittal like OJ Simpson or Robert Durst.

The Daily Beast reported that Acosta told the Trump transition team that he had struck the plea deal because he "was told Epstein belonged to intelligence and he should lay off." While on some level I agree with you that this is the more fundamental and important source of rot and corruption that needs to be excised, it's also the case that many different institutions at all levels of society took part in creating Jeffrey Epstein and they should all be held to account.

Maybe people are just hungry for a "win" here and the MIT Media Lab is an easier/weaker target than the CIA or Mossad. I'd feel bad for them if their behavior in this saga hadn't been utterly reprehensible and telegraphed at so many points that they knew what they were doing was wrong.