Name another big desktop app vendor will hundreds of millions of seats. Name another industry-leading groupware system.
The last big dominant rival MS took down was Nokia's phones operation, but it mainly succeeded there because Google and Apple accidentally helped: Evidence: MS doesn't make phones any more. It derailed the #1 smartphone vendor's own OS efforts and planted an MS exec in charge so that vendor used exclusively MS phone OSes, but it wasn't good enough. The OS failed and the vendor left the market.
Apple is in a different market. Apple sells hardware. Its OSes are free. It also makes a cut on content for those devices.
Character attacks? Have you bothered to read any of the links I have supplied to support my argument?