Kerning is a moral position
Why caring about the space between letters is really about caring about the reader.
People who don't set type think kerning is fussiness. People who do know it is the closest typography gets to manners — a quiet, constant consideration for the person on the other side of the page.
Good spacing is invisible. You only notice it when it's wrong, the way you only notice a room's acoustics when they're bad. That invisibility is exactly why it's worth the trouble: nobody will thank you, and everybody will read more easily.
The reader you can't see
Every typographic decision is a small bet about a reader you will never meet. Set the measure too wide and you tire their eyes. Set the leading too tight and you crowd their thoughts. To care about these things is to take that absent reader seriously.
“Design is just attention, made durable.”
So yes — kerning is a moral position. Not a grand one. A small, daily one, repeated a few thousand times a page.
