Honestly, because of the EPA regulations, it's difficult and expensive to make the small trucks that were so popular in the 1980s and 1990s. Tesla could have cleaned up with a simple single-cab electric truck (especially if it came with fleet purchase options). Because of the economics of the situation if it were priced in the 25-35k range it would fly off the manufacturing lines and become the new standard workhorse for local businesses (think plumbers going out to 5-6 calls a day and then charging overnight), plus it would have the added benefit of a "bring your generator to the worksite" stuff.

They'd just have to be willing to strip a lot of the fancy electronic stuff out for manual things (like manual doors, environmental controls etc...).

pretty standard power trip behavior from an exec,

Definitely not in public, and I doubt even behind the scenes is such behavior normal, despite most execs have psychopathic tendencies for powertrips, they usually have more self control than Musk.

Musk was not just being an asshole, he was being an outright idiot about his own company.

Regarding the Cybertruck, I believe it's a vanity project, because he wants to get rid of the woke image, as if that hadn't already happened.
He wants that psycho right wing macho image, that comes with a "brutal" truck.

Hell, Simone Giertz showed us with "Truckla" that an El-camino/Brat inspired pickup made from a Tesla sedan is more than enough. So the answer isn't all that far from business as usual.

Edit: or just mod a car from 1968 instead: https://www.evbuildersguide.com/electrifying-transformation-of-a-1968-chevrolet-el-camino-beloved-baby/