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Old 2003 player here. Short story long, New Eden started to become less immersive and more grief-friendly around 2006 onwards. Remember Lofty29? yeah that guy, who pretended he wanted to help PvEers and just griefed them. Took a while before CCP added a warning when forming a fleet... this downright POS of an online gamer was the first hero of the Schadenfreude-harvesting griefers, who recently revered Erotica1.
Did CCP watch all the griefers getting secondary accounts to meta-game the game? Infiltration, false friendship (lonely nerds are gullible) and then stealing the mark's assets, pretending to help while waiting to grief, scamming, impersonating etc. "Power of 2"...
Let's cut to the chase Paranoia: you need multiple accounts to put eyes in neighboring systems, whether you are a lowsec/0.0 carebear or an edgy gatecamper
Greed: just read that some guy has a 200+ SP account farming operation going on, and that players routinely know others who have a couple dozens
Malevolence: see second paragraph
This game has become a cesspool of sociopaths and their masochist prey, and they all need multiple accounts (at least two in total, so to scout). CCP coddles griefing, as it brings a lot of revenue in the form of secondary accounts (and remember that PLEXes are bought anyway at some point)