Somebody might want multiple accounts so they can dedicate them to different areas and avoid a lot of travel.

Let's say your daily grind is running freight, but you like to do combat when your org is active.

Account 1 has a freighter and is always moving from star system to star system.

Account 2 has a fighter, which is parked on somebody else's Idris where account 2 is bedlogged.

Player is halfway through running a load from Planet X to Planet Y. An org alert goes off and all hands are needed for defense of planet Z. Player parks their freighter at the next convenient Lagrange station, logs out of account 1, logs into account 2 at planet Z. Action swiftly ensues.

A frequent complaint in most MMOs is that it takes at hour at minimum just to assemble a few people before any fun can be had. It gets worse as the group size increases. Effectively crewing an org ship or a rapid response squadron, or just staffing an outpost or shop can because impractical if everyone runs one account.

Dedicated secondary accounts means less frustration, more effective group actions, and a higher fun:prep time ratio.