For me, tracking the mouse cursor and moving it visually is harder than moving a text cursor, since with a text cursor I can generally look at a piece of text and summon the cursor directly to that location. I have trouble seeing and distinguishing the mouse cursor a lot, and I'm much more likely to overshoot it (or move it frustratingly slowly) than a text cursor.

It just feels better for me to use. I do less squinting. :)