Good support = sending out replacements willy nilly? Doesn't sound like a good business model to me.
I'm saying perhaps someone has costed the difference between say a reduction in failure rates due to higher QC and how much it costs to actually just send out a replacement of a mass produced item, and they have discovered its either a better or equally good business model. Plus it has the benefit of giving people a good opinion of the company.
However I may just be being cynical and my OP still stands that I am glad there is a company out there practising such a CS model.