> These are, in the scheme of things, not exactly massive issues.The perception can be very different though. There are those that really don't like it, and it is rubbed in their face every time they login to their machine. They are small matters, I agree: Metro apps can be completely ignored and most of what I used the start menu for is just as it was (ctrl+esc, start typing, pick from list) and is in some ways better, but it is still a change in look and feel that for a novice user adds friction.
Worse for a marketing/sales point of view: there are people who have not really formed an opinion and have decided to avoid Windows 8 (not upgrading, buying a machine with 7 instead, or getting the option and downgrading to 7 like many did from Vista to XP) because there is a lot of press questioning the UI changes. These people might not know that the change is minor when you consider their entire day, but it is being talked about it loudly enough that MS don't want to take the risk.
Another problem for Windows 8 is of course that many people simply have no real need to upgrade and no end of additional UI options is going to change that. If people have no problem with Win7 then MS can make Win8 look exactly like Win7 and it'll make no difference to that class of user (a very large class of user) unless they offer the upgrade for free.
The only reason I have 8 is that I was rebuilding my main home PC, it was a very cheap upgrade a the time, and I might have need to do Windows Phone 8 development in the not-too-distant future (the SDK for that will not install on older Windows).