As for being handed down the position... maybe Jabba inherited it, but that's not how it works in real-life organized crime. You are not given the position based on genetics because you have to earn the respect of the rest of your crime family. Imagine if Al Capone's son was some pimply faced weasel with no sign of backbone or initiative and then Al gave him the "throne" upon his own death. The family would faction off because there would be no respect for the successor. You have to work your way up through the ranks. If you happen to be blood relative who has worked his way up and is next in line, so be it. But it wasn't you're bloodline that got you there.
As for being handed down the position... maybe Jabba inherited it, but that's not how it works in real-life organized crime. You are not given the position based on genetics because you have to earn the respect of the rest of your crime family. Imagine if Al Capone's son was some pimply faced weasel with no sign of backbone or initiative and then Al gave him the "throne" upon his own death. The family would faction off because there would be no respect for the successor. You have to work your way up through the ranks. If you happen to be blood relative who has worked his way up and is next in line, so be it. But it wasn't you're bloodline that got you there.