Adoption of Mac OS X is being slowed by 9.1, a news article claims.

Apple's method of shipping dual operating systems – Mac OS 9.1 and Mac OS X - on new Macs is reproached by Charles Haddad in Business Week.

Haddad condemns the company's reluctance to ship Mac OS X as the default system. Mac OS 9.1 is described as an "increasingly antiquated operating system" that "drains technical resources" and is a "distraction."

Haddad claims present OS X users are first adopters, and that others will switch only when big guns like Adobe and Microsoft optimize their applications for the platform.

The author estimates that OS X should reach critical mass in around 18 months, triggered by Microsoft's release of version X for Office this November.