OSNews points to a ZDNet article, Microsoft: 'Open Source Is Too Complex'. “Although open-source software can be customized to meet a company's specific needs, its inherent complexity could dent the profitability of independent software vendors, says Microsoft. “One of the beauties of the open-source model is that you get a lot of flexibility and componentization. The big downside is complexity,” Ryan Gavin, Microsoft's director of platform strategy, said.”
An ISV has to know what they are getting into, and have sufficient support to deal with the challenges of many platforms. The same is true if you choose to support Windows XP, XP Home, XP Media Center, XP Tablet, Windows 2000, Windows Server 2003 on standalone, networked, workgroup, domain and Active Directory models. The claim that supporting Linux because there's more than one vendor (all of the majors adhereing to the Linux Standards Base) is FUD. If you have to support home users with Windows 95 or do-it-yourselfers with a hand-built Linux kernel, the challenges are the same. Their claim to ISVs that Windows is easier to work with may be easy to claim, but I'd like to see Microsoft prove it. Truth Happens. Unbend the Truth.
Microsoft claims that computer technology is complex, and they are smarter about making those decisions than their customers. If they are not careful, they'll prove that. The smart customers will leave.