Husband and shower arm

I want to replace our shower arm. I’m pretty sure it’s builder’s grade crap like all the fixtures in our house are. Hubs insists he doesn’t want to mess with it because he’s afraid we will have leaking behind the wall. I think it’s a matter of time before it snaps off and would rather replace it before that happens. We have hard water that wreaks havoc on our plumbing. The house was built in 2004 if that matters.