It's not just the macro command that's missing. You cannot hide them from the HUD Layout screen either. (They appear in HUD Layout, but it only lets you move and re-size them. The show/hide toggle that's available for everything else is disabled for job gauges.) That suggests it's a design decision rather than an oversight.

That said, it's not a design decision I like, so I'd second the request for the ability to control them.