First it's clear that lots of people buy trucks. But from my experience only a fraction of the people who buy trucks actual use them to any extent. That is people buy them for commuting and as a status symbol. I rarely see a truck with anything in the bed or with scratches and dirt from being used to do work.
So what's shaky is I took this truck analogy with PCs to mean that PCs will be around and useful but only to "professionals". This may be the case with PCs in the future, I'm not arguing that. But I don't think that's true of people who buy trucks. Yes farmers and construction people use trucks, but they're really in the minority of truck drivers.
And this is not even considering SUVs which are really just trucks without a bed. My understanding is they're manufactured with the same frame and engines, and are considered trucks by regulators (so they have laxer safety regulations).