Not a cathedral because it was not on a software but a near-monopoly market? I love taking metaphors too far, so I'll just notice that "near-monopoly" is what cathedrals are all about.
Microsoft didn't architect their software as software, they shaped it as tools of monopoly enforcement.
There are numerous accounts from people involved about how marketing decisions relating to cutting of 3rd parties or trying to bludgon somebody into submission caused them to cripple their own software and its architecture.
See the evidence in the M$/Novell case for ironclad evidence of this.
This kind of passive-aggressiveness only reinforces the grumpy-old-man stereotype and makes it really hard to take you seriously.