God Emperor Akhenaton
Quality control is a lie. If such a thing was regulated, then the dv6000 wouldn't fry itself to death.
Quality control isn't regulated. Not in the way you're thinking of. The underlying technologies and functions are regulated (by IEEE, FCC, etc) but there isn't some regulated body that is independently testing every computing product from every manufacturer in ways that YOU want them to, such as processor/GPU temperature at idle/load, keyboard ergonomics, relative build quality, etc. Because there is no regulated body,
this is why review sites exist. Yes, those sites serve a useful purpose and fill an actual role.
But HP isn't going to clog their heatsink with dust, use an aged, dried out TIM, or use a fan with a failed bearing in their own testing. SOME dv6000-series systems included somewhat higher-end hardware that pushed the limits of the cooling solution that line of chassis provided. When tested, those systems may offer sufficient cooling and performance. In the field, in the hands of users, that's not always the case. There are tons of systems from tons of manufacturers that have failed to deliver sufficient cooling under so called "real-world" scenarios. The only reason that the dv6000-series is even remotely special is because HP used that chassis design for a while and it sold reasonably well. Various dv6000s ran perfectly fine, while others were more likely to run into problems as their tolerances were more limited.
And why are you so focused on the dv6000? It's a chassis design from 6-7 years ago. The only models with consistent issues used power-hungry AMD mobile processors. It's really not worth getting worked up about.