The jury system has *not* been abolished. Several things to bear in
mind...first, even now, choice can dictate a jury vs. judge trial (it is often
in the plaintiff's court, so to speak, to choose which one is preferred in
civil trials). Second, if you look back at the history of the US, even in
jury trial days, you had Circuit Court Judges who traveled through rural
areas, frontier and unconsolidated regions, and held court by themselves.
Babylon 5 is a unique environment. There are only two basic types of
people (speaking only of humans for now) around: those employed by EA or the
station (conflict of interest), or travelers, who won't be around long enough
for a prolonged trial. So in that kind of situation, the Ombuds arose...a
2258 version of a Circuit Court Judge.
It's absolutely in line with what's been done in our own country.