You think it was bad that the tzar got Merced? While it’s sad that his children got killed, it was also politically expedient. We’ve seen time and time again that allowing the royal line to continue is just begging for counter-revolution or the occurrence of a government-in-exile. The tzar and his family benefitted from a system (which they maintained themselves) that killed children daily. The royal family encouraged pogroms.
While the murder of the inheritors of the Romanov line is regrettable, it is in no way some “great crime”.