>>OK, but IBM's competitors were comparatively weak with less credible support/education channels and lower build standards. That's not what MS is facing.

Yes, that's an excellent point. IBM had no serious competitors with the technical and financial scale of Google or Apple.

However, MS shares another advantage that IBM had with the business world- a huge installed base with a vested interest in IBM's success (mainframers like me.)
Anything with those 3 blue letters on it was much easier to sell to business clients, so we stayed with IBM wherever possible.

My life and the lives of my clients would be a lot simpler if we could stay in a familiar tech world as things evolve, so our bias will naturally be toward MS and the usurpers will have a steeper hill to climb.