This is intentional, as an empty homepage is not a typical user scenario. You can hide the categories label via custom CSS, or custom JS if you want to hide it only when there are no categories.
New User Experience
Or NUX for short. Was thinking of a potential plugin for this at some point (ex, arrow pointing to register button). @trevor, I remember some initial version of convoe had some help tooltip that was pretty cool, it zoomed across the page and stuff and told you about the keyboard shortcuts, etc. What was this lib or was it custom?