It depends. I've got a couch that's torn to hell due to my cat. It needs to be reupholstered. Now if I cared about, say, a NEW couch, I'd train the cat out of it or put some protective measures on the areas that the cat tends to rip up.
You know, because nothing says "high class" to your house guests like a nice place with one ratty POS couch.
Same thing with a car. I paid too much for my car. It looks nice. I'll run it into the ground. However, where I live I tend to get a ton of paint chips and stuff like that. That means that *I* will have to pay to get my car fixed up. I need to do this so the dang thing won't start rusting (unless the hood is aluminum and will only oxidize a bit?) which will cost even MORE money to fix or replace.
By using a bra on the front, I can reduce the number of times during the car's usable life that I need to repaint or replace the front hood due to road wear and damage. I live in the midst of a city undergoing a few years of construction as they widen the main road from 6 lanes to something like 12 and replace all the bridges over that road. It is literally a multi-year plan. I drive through that construction zone daily to get to work.
I also don't know the road conditions elsewhere and I tend to take 900+ mile trips (from Denver to Dallas, or from Denver to D.C for instance) where who knows what the 'ell I'll encounter.
And then there are the trips into the mountains. The wonderful poorly-maintained mountain roads.
Aesthetics aside, it's a practical matter for me. There will be no next owner. As such, protecting the vehicle from damage is of concern to me since I'll be the one paying to get it fixed. I view it as preventative maintenance in much the same way that changing your oil keeps your engine from needing to be replaced.
I'm not made of money. This is the only car I drive. I can't afford to take time off of work to just repaint the car's hood whenever it gets a nick. And touch-up paint is, approximately, extremely ugly (used it all the time on my old Volvo 240).
I take some amount of pride in my vehicle. I got an R/T because to me it said "performance" and "top of the line" for that class. I don't want to drive an R/T with a bunch of chips and rust spots on the front.
When I get a new couch, it will be protected from damage. If the couch were in good shape before I got it, it would have been protected from the start. If I had the money at the time, the Intrepid would have been protected from the start. But I didn't and now I'll need to get the chips taken care of. But the bra helps prevent more and will help prevent more once I get the hood fixed up.