Special vehicles are special primarily because of their rarity. If we hand them out like candy, they will become regular vehicles. Take CLO swat-tank-thing vehicle as an example, there is absolutely nothing special about it besides the fact that it is limited to CLO only. Had we started handing those out, they'd be irrelevant and "old news" mere weeks later.
The same principle applies to plenty of other concepts found on the server, such as pick-up items or spawns and jobs/abilities. Things are set up this way in order for players to have some sense of progression while playing on this server. The more is available off the bat, the less goals you have to work towards achieving.
In this specific case, the vehicle only exists on the server for purposes of CLO vs. DE events, had those two organisations disappeared, I doubt we'd be seeing any Hydras at all because they do not fit into the type of gameplay that the server revolves around.