This guy ties grill height directly to fatalities. They really are a menace, but it's by design. Quoth one designer, "I want it to look like a fist coming through the air."
I'm reminded of an article[1] a while back about trucks getting bigger where a commenter pointed out they are also getting "meaner" looking. I'd argue that maybe aggressive, belligerent, menacing truck styling is popular because [some] Americans themselves are getting more aggressive, belligerent and menacing. Vehicles have traditionally been used by people as personality extensions, so this "My truck should be like a big fist" attitude shouldn't be surprising.
Fascinating. An interesting part of that document:
> The point of these explicit associations with violence was not to reflect a growing brutalisation of society, but to identify people the market researchers describe as “especially self-centred”.
Which would contradict my guess: They're actually going after self-centered buyers, not necessarily angry, belligerent ones.
1: https://news.ycombinator.com/item?id=32425028