Why shouldn't I expect an off the shelf item to work, to suggest otherwise as you do is just ridiculous.
It depends who's making it. There is no one way to make a PC, and therein lies the problem. No one actually makes an entire PC from scratch, they are assembled from discreet components, and the choices you have when building one vary massively... and hence quality.
Macs are all the same. Only one manufacturer makes them, and they are all made in the same way, by the same company in the same factories, and the parts are all supplied by the same suppliers etc.
Imagine if Ford allowed their to be manufactured by anyone.. and you could choose all the parts that go into it. Eventually, there were hundreds of companies making them. Then eventually the parts themselves were being sold separately, and even third party manufacturers designed and built their own parts, and sold them separately... each part never really being thoroughly tested to see if they work with other third party manufacturers parts... and then the general public and smaller companies started manufacture too.
See my point? Pretty soon... Ford cars would become a product of variable quality; one you could not actually say with any certainty would be as good as any other Ford car..... essentially because it wouldn't be a Ford any more, nor have anything to do with Ford.
This in itself doesn't mean that the product isn't capable of being excellent... it's just that it's no longer one product.. some are crap, some aren't.
So yes... you can get a crap, off the shelf product. It happens all the time, with all manner of products.
Strangely my off the shelf Mac has worked perfectly for 5 years.
Of course it has... it's a quality product. I've said Macs were crap... . I like Macs.... sometimes. I use them all day, 5 days a week. Which is why this is not a PC fanboy rant. Macs are absolutely fine. They are however, stupidly expensive, slower, less upgradeable, and let's be honest.... just form over function. Any company that compromises performance over looks with a computer product is selling a status item as much as a utilitarian item. The new iMacs are a case in point. The Mac Pro while excellently built is just massively under specced for such a horrific amount of money too.
You're just not really getting your money's worth. The MBP is the only product that represents any real value, but it's still stupidly expensive. The retina display is a non starter for me. The actual OS desktop is scaled up and re-interpolated to the retinas higher resolution... it's not running in native res. Good job too, as everything would be too small to see on a screen that size, with that resolution. The only advantage is you cannot see the pixels. When desktop monitors of a decent size start to use panel resolutions like that, then I'll sit up and pay attention. No matter how great a laptop is... it's still a laptop. You can't really do any serious work on a 15" screen.
Those questions - all genuine, asked cause no real idea, so the ram question. Makes a nice noise as it flies past.
Your benchmarks, did run them on my MBP came out exactly as listed. I did notice it never pushed my processor past 75% or used more then half available ram. Either I'm missing something or they didn't really push things?
As listed? Just run it, upload the results to the geekbench site, and post a link to it on here so people can see it. The website explains what all the separate tests do. Sometimes it's testing RAM subsystems, sometimes it's testing specific math performance, so the processor will not be running flat out all the time, no.