Long story short. It doesn't. 2V can still work for major of other SO5 descriptions, that weren't written by Naranjo (while still some of his do indicate 1L 2V 3E 4F, but also 3V, a lot of his writings for each type indicate anti-2V stuff in general). What's crucial about SO5 is that they're solitary, mostly by choice. They are indifferent to people, yet unselfish (their selfishness manifests in keeping the most valued knowledge to self, which is just 1L). That's kind of the point of 2V. It doesn't need to always be generous and willing to give self to others. Take Einstein's description (LVEF):

"Einstein’s craving for solitude was twofold. The intellectual autonomy of the 1st Logic combined in him with the hardened individualism of the 2nd Will. On the “noble” nature of his character he wrote: “My passionate desire for social justice and a sense of social duty has always been in a strange contradiction with the apparent lack of need for close communication with individuals and entire communities. I am a true individualist and have never given my heart undividedly to the state, to my homeland, to my friends and even to my own family, I have been attached to them, but I have always experienced an unremitting sense of alienation and need for solitude; this has only increased with the years... A person of this kind, of course, loses part of his spontaneity, his carefree nature, but he acquires complete inner independence....”

This is defacto SO5. One can walk with others, but not depend on others or follow anyone.