That's not entirely true. Certainly with the big builders there's a certain incentive to go cheap, but interior stud walls offer significant advantages over alternatives. For one they're quicker to build, they're lighter (you want to suggest building brickwork on a second storey floor with no support underneath?), they allow a certain flexibility when pulling wire and - believe it or not - they actually block sound better than other wall types as long as they're constructed right.
Solid walls carry sound like nobody's business. A properly built stud wall deadens it with the use of air gaps and insulation. They also hold heat in better. I should know, I'm living in a small block of flats I helped build and I can often have trouble hearing the wife just one room over when she's shouting at me.
Now it's possible we built to a higher standard than the rest of the industry, but I doubt it. We built to the regs as written.
You will not see exterior stud walls in this country ever. The closest you'll get is SIPs but those require cladding, either in the form of external decorative cladding or a regular brick skin with a minimal cavity.