EQ2 Private servers allow players to join servers that are basically free. Players tend to join EverQuest 2 Private servers for 3 main reasons of their gaming enjoyment.

Reason 1 is a player wants to skip the fees. With average online servers players are forced to pay around 10-15 dollars a month to play on a real server. When people create private servers it is 100% free to the community. As well players can then keep a stored character forever without being forced to actually pay for it.

Reason 2 is players can test out new things. For example lets say you want to see what 2 different weapons can do. Well if you played the official servers you might only have enough to purchase one of these weapons and have to wait awhile for the next one. With a private server you can instantly have both weapons and see which one better fits you.

Reason 3 is players can test out cheats / bots / hacks on private servers. While maybe on the official servers trying to figure out a new exploit would get your account banned. However if you are on a private server most of the time they have little or no rules. This allows you to easily test out new things that you can later use in the official servers.

Keep in mind private servers are highly illegal and owning one / creating one could get you in serious financial civil suites or maybe even criminal cases against you.