Back in the day, we had BBSes. It was a really cool thing for some high school kid with an extra phone line to set up one of these things and play God with his users. Unfortunately for the prospective deity, you had to GET users first. I had a bunch of friends who tried to run BBSes, and from their efforts made a few observations in an incredibly hackneyed and unscientific way. This will probably make any sociology students shudder, so I recommend turning away now.
There are 3 related reasons people may prefer a particular system of government or BBS over another.
Technical—More nodes, games, faster connection speeds on a BBS. Higher level of civilisation and better quality of life in a government. There are the result of money, and a natural outcome of a well-designed system.
Communal—This refers to the personalities, goals, and general social bent of the system, and is a reflection of the general attitude of the common members.
Hierarchal—This is the relation of the ruling class (sysops, cosysops/governors, aristocracy) to the commoners, and the social stratification of the commoners as well.