Those "forward leaning grills" you're crapping on are just flimsy plastic with a bunch of air behind them. If they strike a pedestrian at any speed they deform and crumple and whatnot and the pedestrian winds up on the hood.
While not styled to lean forward like what Dodge does pretty much all the tall bulbous front ends that HN hates and are found on modern cars and crossovers are designed like this. A bunch of plastic with air behind it is the primary means by which OEMs meet the European pedestrian safety requirements. The styled plastic provides something that's softer than the quasi-structural radiator core support that all the front end cosmetic stuff attaches to for the pedestrian to hit.
The context of my comments was someone asking about designing like the 1950's. I was trying to explain why we can't legally build those exact cars.
If you ignore that bit of the conversation, you're right that in a modern car you've got a good foot of material before you reach the first bit of metal, which is the hood, and the hood as some others have said is designed - today - to have a little give when a human encounters it. Something I actually have limited first hand experience in.
A lot of those muscle cars though, the hood of the vehicle extended all the way out past the bumper. So you wouldn't be able to build those exact designs. But maybe there's some compromise that incorporates your points with mine? The modern Mustang looks like an homage to the Mach era, but it's a shadow of that bad boy, and it only comes after decades of wandering in the proverbial desert.
The problem is always when you ask why generations of smart people didn't see the obvious answer, occasionally the answer is only visible to outsiders (curse of knowledge) but more often the answer simply doesn't work because of other, bigger concerns than aesthetics. For every time Beginner's Luck works out, there are tens or hundreds of cases of Chesterton's Fence.
While not styled to lean forward like what Dodge does pretty much all the tall bulbous front ends that HN hates and are found on modern cars and crossovers are designed like this. A bunch of plastic with air behind it is the primary means by which OEMs meet the European pedestrian safety requirements. The styled plastic provides something that's softer than the quasi-structural radiator core support that all the front end cosmetic stuff attaches to for the pedestrian to hit.