I suspect part of it is brand differentiation. All the trucks on sale at the moment broadly look pretty similar so brands are essentially just using details to mark them out from the others.
Seems to go in waves. The late-90s trucks all looked pretty different to each other, but go back to the mid-80s and line up an F150, a Dodge Ram 1500 and a Chevy Silverado next to each other and you're essentially looking at boxes on top of boxes with subtle differences in the grilles or positions of headlights to differentiate them. Go back to the 50s or 60s and there was once again a lot greater difference.
Design, and taste will always evolve. Pickups aren't likely to disappear any time soon so perhaps in the next 10 years or so the designs will be more to your tastes. Or in ten years you'll look back on today's stuff and not think it's so bad.