Help understanding this shower setup

What's the deal with stand-up showers (no tub basin) that have a tub spout about a foot off of the floor, and just a single shower head? I'm assuming that this is some sort of retro-fit where they used just a standard valve, and then the tub faucet as a diverter to turn the shower head on? I've seen this in a few new bathrooms, and now just on "Holmes on Homes" on HGTV in a bathroom they just re-did.

What's the purpose in doing this?

Search 'toe tester', and you'll find this discussed ad infinatum...

It is a useful addition to showers so you do not get hit in the face with a blast of cold water when you turn the valve on. I do it in my own showers and wherever I can convince the customer of its advantages.