I'd have to disagree with that. A bit anyway.
I would say they have them because packaging the setup is much easier.
Also the low to midrange punch from a roots style blower has negligible lag and is usable in the most commonly used rpm range.
The first roots setup was released in a truck too. (Lightning) It was never meant to have to the crap spun out of the engine to make power (ala a centrifugal S/C) and a turbo setup entails a whole lot more work, parts, Heat, and engineering to produce.
