i guess it is a matter of consistency and preference
You are correct, my site was working and looking like yours.
However, as users navigated into categories, I would prefer the top portion look the same.
Before I changed it, the top-level and category-only levels, had a white background and blue-text breadcrumbs, but when you got to a category with products, the header section was blue (colored) with blue (colored) text -- in my style, the text was indistinguishable from the background.
Now, my header is the same, whether it is the top level, a category with only sub-categories, or a category with products in it.
See the screen-shots for a top, cat-with-sub-cats, and cat-with-products navigation -- the top portion w/ breadcrumbs is the same...