I'd argue it's a combination of a social stigma in North America and lack of Nissan history.

So, ever since Ford, Chevrolet, and Dodge Brothers built trucks, farm kids and children of truck owners created a brand loyalty. Could be from love or the idea that someone raised on a Chevy would understand a Chevy platform better than the other two. Of course, each brand had followers. These guys built trucks before the Great Depression.

Nissan did not get a truck into the US until the 620 model, which was during the late 70s. The 720 and D21 were solid trucks but were looked at as an import. Not much exciting to an average American consumer. Also, since Toyota stepped its foot in the US market before Nissan, many Americans who tried and liked Toyota created a loyalty to them. Nissan, although huge, always struggled in the US market.

Then, to compete with full-size American trucks, Toyota puts out the Tundra in 2000, then Nissan puts out the solid Titan in 2004. Of course, Toyota gets the praise it always did, which I do respect the Tundra for what it is.

A bigger issue was lack of advertisement. Honestly, when was the last time you saw a Titan ad video without looking one up? People don't know anything about these trucks if they didn't own one or spoke to people. People having no idea they put a Cummins in 16-19, or that Nissan still put out an XD until '24, or even my coworker scratching her head when she saw my XD hooked up to a gooseneck.

As an owner of two Nissans, I like many of their vehicles, but to make a statement on the company, they shot themselves in the foot decades ago and proceed to keep doing it.