Because everyone buys just one type of full size truck, and this wasnt it

It is probably the single most competitive segment in the USDM. Every other company's products are simply better.

What I am surprised is why didn't they spread the costs to develop and manifacture this truck with someone else. Nissan is tied up with Mitsubishi. Mitsubishi used to have a smaller truck that never sold extremely well, but it sold well enough. Nissan should have shared the platform with Mitsubishi to spread costs like they are doing with the Rogue and a few other products.

You could get better for the same or less money.

Here, you either buy American or Toyota.

Trucks are more of a status symbol than a utility vehicle. So for the status you get a big F150.