From a repair point of view, he's right.
A faucet installed on a deck is pretty easy to repair and maintain. Replacement of the hose is another matter.
A wall mount hose attachment is forever in plain sight. If you had an access panel for a repair down the line, then it wouldn't matter, but that tub looks pretty closed in. However, I've seen plenty of these installed on decks. I don't so much mind installing them, they should last years. Going back to service the hose? Yeow!