It's now been six months since Microsoft (MSFT -2.45%) launched its controversial new platform. Windows 8 has been derided as confusing, and the software giant has received no small amount of criticism over its choice to ditch the Smart Menu. Microsoft may be about to address some of these flaws with Windows 8.1, known as "Blue," but the Windows brand is certainly hurting right now. Apple (AAPL 0.52%) is now taking the opportunity to kick its longtime rival while it's down.

In an interview with CNN Money, Windows exec Tami Reller said not to "expect an iTunes app on Windows 8 any time soon." The ball is in Apple's court, as Reller added, "iTunes is in high demand. The welcome mat has been laid out. It's not for lack of trying." That's something of a blow to Microsoft's ambitions for Windows 8, particularly since iTunes is the largest digital music store on the planet.

iTunes will still be available in desktop mode, since Windows 8 is backwards compatible with legacy apps. Reller was specifically referring to a "Metro" styled version of Apple's jukebox. Microsoft's big interface push with live-tiles will be undermined to the extent that high-profile developers shun Metro.

That also means that all Windows RT devices, such as Surface RT, will have no way to get iTunes since Windows RT doesn't support legacy apps and has to get all content from the Windows Store. Windows RT users and Metro enthusiasts are just out of luck.

The decision is in contrast to how Apple played iTunes a decade ago. While iTunes and the iPod originally launched in 2001 with only Mac support, the decision to expand compatibility to Windows in 2003 did wonders for the iPod business as it significantly boosted the iPod's reach and appeal. It's like night and day.

Source: SEC filings. Calendar quarters shown.

The big difference between now and then is that Apple has grown its PC market share since then, and is in less need of a Windows boost. Additionally, addressing the Metro subset of the broader Windows ecosystem wouldn't be much of an incremental gain for Apple, since most Windows devices can still use iTunes in desktop mode.

Netmarketshare's stats show that Apple's not missing a lot by excluding Windows RT, which peaked at 0.02%. The absence of a Metro iTunes won't bother Apple much, but it might peeve Microsoft a little bit.