I'm not saying that they aren't capable of doing it. Really, the release on July 29th may be the most polished OS ever released. I was digging Windows 10 while I was using it. But nVidia hadn't released a driver for my video card, so I rolled back. I still have Windows 10 reserved on all three of my computers barring some disaster.
All I'm saying -- and I can't fathom why this is radical or controversial -- is that people having issues with current pre-release versions are not being unfair in voicing their issues with the product. If everything is fixed between now and release, then great. But for people that might be thinking that this new OS is going to be the greatest thing since sliced bread based on positive testimonials, the negatives ones are worth acknowledging too.
That's not being unfair. Nobody is saying that MS are a bunch of shitty hacks who can't code an OS. But it's silly to say you can't comment on stability in pre-release software because it's a given that every issue will automatically be fixed by release.