Sentencing has never made much sense. Depends upon jurisdiction, how many charges prosecutors can tack on, how many you end up going to trial over, how many you get convicted over, and who is responsible for sentencing (in some places the jury sentence, in some the trial judge, in others sentencing is a separate proceeding with a separate judge).
One of the big factors here is that Masterson and his lawyers still deny everything. He didn’t cut a deal, hasn’t shown remorse since he hasn’t admitted to any wrong-doing, and the judge chose to sentence consecutively. First trial was a mistrial, second trial got 2/3 convictions, and apparently they intend to appeal. So depending upon appeal, he is currently facing somewhere between being acquitted on appeal to facing life in prison. In a lot of cases like this, some sort of deal is cut on lesser charges or lesser sentencing in exchange for admitting guilt and not dragging this on through appeal, hence typically shorter sentences. Masterson/his lawyers are instead rolling d20s and the current outcome is a 1.