If you approach this from a more analytical level, it is much easier to grasp.

1) Welding highend steel tubing (lugged or not) is not rocket science.
2) Neither is it a high and incomprehensible art form.
3) Riv provides high end one-stop-shopping for a particular type of customer and cycling activity.
4) For some cyclists, that combination of quality and service is enough, even if at an unnecessarily high price.
5) Very strong brand, like Rolex, which is not the best automatic watch in the world.

Riv offers quality products with a strong brand.

I, on the other hand, enjoy building up my own bikes for specific purposes. The world is full of great frame builders.