I could SO be a Hermit in real life instead of just esoterically. Shining the Light, but from my own personal mountain top...
The Hermit appears alone on the mountain top to show he is at One with his own interior Self. Yet he still shines the Light for others.
The Hermit is Lighting the way for those that come behind on the Path. Making it easier for them as someone once made it easier for him.
The Hermit has learned to master the Strength found by working with the lower self and subconscious.
Instead of fighting them or trying to suppress them we must work with them and use their massive Strengths in our favor.
See what I did there? Hint, the previous card is Strength. :-)
Having learned to use the 'animal' nature found within The Hermit is ready to stand alone and take full responsibility for his own actions.
No more blaming those 'dang' base instincts. No more blaming anything really.
The Hermit fully realizes that they and they alone are responsible for their own thoughts, emotions, and actions.
This is why I believe The Hermit is shown alone on that Mountain top. They have reached the summit, now they in turn help others reach it.