Oh...so since you've always done it a different way it's wrong...cool story bro.
Did you look at the link I attached? The horns are behind the bumper and aren't blocking anything. Have you looked behind the grill at how much room there is? We were just discussing adding a light bar to mine, I can still fit 2, a 30 and a 40 if I'd like, even with the airhorn and the 4 whelens I have in my lower bumper. Kind of like how Yukon has 2 bars, a winch and 2 whelens....no issues with heat. But she's my grocery getter/ soon to be mommy mobile so I really don't need that much light.
Plus, regardless of the girls lack of taste in color schemes and filthy truck, you are assuming that she came in and said install these horns under the grill. My guess is that she said install these horns and they(the shop you went to to install headrest dvds, which in my opinion are gay on an off-road truck, but as you said, everyone has their own tastes, I guess) picked under the grill because its easier than under the bed. Ps... Depending on your offroading situation expect occasional water/mud horn under the bed. That's where Yukon's are installed.
Now I may seem a little snarky, you can blame that on my being pregnant or not... Either way... Opinions are like ********... You're opinion is that this is not a good mounting position for horns and this poor, hopefully color blind, chick deserves laughed at for it, my opinion is headrest dvds are for tools..
But truth is that this is a perfectly fine mounting position for horns, only drawback as I've already mentioned would be front end collision/projectile.