and speaking of innovation.. i suppose linus and OSX are based on that innovative brand spanking new OS UNIX
Just because something has been around for 40 years in concept and philosophy, doesn't mean it's outdated. The internal combustion engine is a good example. (Of course, the modren engine is a vast improvement over the original designs, but that's not the point. I'm talking about the principles here.)
The principles of Unix are consistency, modularity, and one tool to do one job and nothing more. On top of this is a file-based device layer, a certain way of representing a filesystem, certain filesystem layouts and standardised tools (cp, mv, ls, ps, whoami, su, top, and all the other ones).
The fact that these 40-year-old principles are successfully used in Linux today shows how sound they are. You only have to play around with a Linux distro like Gentoo to see how innovative things are.
And in any case, by your arguments, WinXP is outdated as well, as most of the code is about 3 Windows releases old. However this is different. It's the principles and algorithms that persist under Linux, and they persist simply because they are efficient, because they are consistent, because they are an accepted standard.
Windows code persists because Microsoft knows it's cheaper to repackage than to rewrite.
Open-source codewriters don't get anything for their work, besides the satisfaction of creating a program, and the respect of their peers. The very reason they're doing it is to write good code; hence, they make it as good as possible.
Microsoft are in the business of making money. The fact that they write code to do it is incedental. The business comes before everything -- product quality and business ethics included. So whenever they can cut a corner, they do. Whenever they can get away with a makeover instead of code refinement, they do it.
So, what I'm trying to say is that the presistence of design principles through time is a good thing (as long as the original principles are sound, which in the case of Unix, they are). The persistence of buggy code and badly thought out or nonexistent principles, hidden by endless interface redesigning, is not.
Linux is an innovative OS based on the Unix design, which has stood the test of time.
Windows is a tool that helps Microsoft make money through MS Office, and does what it's supposed to do very well -- that being, make it as hard as possible for the end-user to use alternative software and continue to share data with other MS users.