There is no such thing as the "average" user "average is just a statistical construct
The are "majority" Users, the person who does not enthuse over a PC system, does not write internet blogs about PC systems, though some will use their PC or laptop or tablet to write a blog on a subject that is of interest to them, maybe it's collecting coins, stamps, autographs or whatever. to them, who are in the vast majority, a computer is a tool to get something done, not an end in itself.
another part of the "majority" are those who use a PC system of some form to assist in their work, again these users look at a computer as they would a photocopier, or a Phone.
These users will use a computer until it wears out or their company installs a new one, they will use whatever operating system is supplied, for most of them the OS is irrelevant, they probably see the desktop, or other start-up screen for a minute or so a day
These users are application centric, they care that their word processor processes words, their spreadsheet crunches numbers, or their facebook works.
This is the market that Microsoft has to satisfy to do this they sell operating systems via box shifters like Best Buy, or DSG in the US or UK respectively, or they sell volume licences to governments and multinationals
We hear figures of 1 billion PCs in use, over 99% of these still have the OS that was shipped with them and will never have anything else.
We as enthusiasts or professionals will eagerly await the release of Windows 9 and 10 and so on, but we will actually make very little impact on the future viability of companies such as Microsoft :)