2- They really do use it; it is very practical, everyday. For real.
On this one I call BS. For the reasons already mentioned. The overwhelming majority of pickup owners do not own them for practical reasons. The majority who say such are self deluded. I wonder if these people even know why they bought it. Hence, the status symbol theory makes the most sense and fits the data.
If it was really practical, the owner would have the financial numbers off the top of his head, because they would be talking about business expensing the truck. And a successful business owner knows his costs to the penny.
I bought a pickup rather than a regular car for practical reasons:
1. I need to haul race bikes and trailer to track (5-10x per year)
2. I go off roading with it (1-2x per year)
3. I use the bed for carrying large items 10-20x per year
4. I need a daily driver that ISN'T my supercar
Given all of the above, it was either:
A. Get a daily driver nice car for 1/2 as much as the truck (saving ~$4k per year), and rent a truck 40-50 days a year (costing $1-2k per year) and give up off roading with my family
Or
B. get my truck, which also gives me a GOOD vehicle, and the convenience of not having to go to rent one. Given the number of times I need it, that time is worth WAY more than the truck payment.
Also, my truck pulls 0.71g skidpad (vs 0.9g miata, or a difference of ~10% in speed) and does 0-60 faster than all the Miata's except the mazdaspeed and the latest version, which only beat it by 0.7s (6.9 vs 6.2sec)
So how am I not being practical or deluding myself? My truck was absolutely cost effective for what I actually use it's pickup abilities for, gives me a vehicle to use for off roading with family, and performs on the street within 10-20% of your miata?
As for sportscar racing and track days, or fun driving, well, I have a car for that.
So I think you need to add a third option, for those that need a SECOND vehicle.