[gerdesj]

I dimly recall it being noticed at the time but I suspect it was really a convenient side effect ie a contributory factor and not the primary reason.

I think "branding" is far more likely. google.com is the brand and a single entry point landing on search which then points you at what you "need". Note how you search and can click on the buttons underneath the bar to move into images, maps etc. Maps is just another specialized form of search.