Those are high-cost manufacturers who produce business-grade equipment.
When it gets to consumer-grade stuff, the margins are so low that those
shops which play in that area cannot afford their own designs. And don't
forget mainland China, Indonesia, and other places where a lot of
"no-brand" stuff is produced.
Actually looking inside PCs is often quite enlightening. I'm quite amazed
how most of cheapo stuff manages to work at all. Like, missing or leaky
capacitors, plain conductors instead of inductance coils, peeling PCBs,
missing ground wires, unevenly soldered connections, overclocked CPUs and
PCs are very poorly designed, too. If not for Billy's flaky software,
that would be quite evident.
Anyway, this is drifting off-topic. My point was that CO-grade, non-stop
equipment has very different design requirements from PCs. So is military
stuff, but somehow nobody complains that MIL-spec equipment is so
expensive and so few-generations-behind.