To be perfectly honest, I have never had a laptop that has lasted more than 2 years without something going... Normally just wear and tear. Battery life is also a common problem, and the reality is that batteries are expensive. If two comparable laptops are £100 apart then you can assume a big part of the saving is in the battery. Cheap batteries lose their ability to retain charge much faster.
The question is, are these things actually faults? In the same way a cheaper laptops battery is more likely to fail and the case more likely to crack over time, I could state that a cheap laptop is faulty because it's not as fast as a much more expensive one. It's all down to money spent/saved on components and materials.
Given that even a shoddy cheap laptop will typically function for at least 4 years, even if the case is worn and the battery flagging, then you could argue that the build quality has still exceeded the lifespan of the technology inside.
A quick glance at some of HP's products demonstrate beyond question that they can build something that will last rough treatment for years, look at some of their commercial printers. But frankly the sensible balance between spec, price and build quality for laptops and home computers is probably about right. Better would be nice sure, but having more money left in your wallet when you do buy is equally nice. And having owned and bought god knows how many laptops, I would say HP are among the better still.
Dell laptops tend to be tougher, although you can often see the premium. Even then Dell put out a range of Inspiron laptops a few years ago that crumbled like plaster.
As for Apple laptops - Yes, the build quality and in particular the battery technology is about as good as you will see anywhere. But given that Apple's are 50% fashion statements and limited in terms of power, what an earth is the benefit of that build quality and battery longevity? Is a fashion concsious Apple user really going to use a slow, out of date model in 6 years time simply because it refused to die?
My point is (and sorry for the rant!) that when we go to buy a computer we have in mind the sort of value and performance we are after, these tend to be our chief concerns. The manufacturers are doing their best to meet these concerns. The issues with longevity in a lot of tech, could be argued to have started with our own preferences and demands as consumers.