I completely agree with that, Microsoft's foundation was software. What is intriguing is that when they decided to "go hardware" (which started with Mice and Keyboards and later game consoles, tablets, phones, and laptops) their execution strategy didn't evolve to making their own silicon until much much later. Apple was much more aggressive here with the PowerPC alliance after Motorola let them down followed by later moves into chip design.

I am always fascinated by seeing how the "core competency" of a company constrains its execution options later in its existence. Sun, for example, really was a 'sales' company first and it couldn't "sell its way" out of the wave of Linux clusters that started displacing its servers. Now as a hardware company it too was let down by Motorola and that was some of the genesis for SPARC much like Apple's move. But as a sales company Sun kept shooting anyone who used their "open" architecture CPU by ruthlessly out selling them.