Software development is to Microsoft what olive oil importation was to the Corleone family: yes, it's their business and they're good at it, but no, it's not exactly how they got rich.

You often have to be lucky (in timing, in marketing, in whatever) to be the first. Once you've proven the market, later entrants don't have to be lucky. You've already given them a path to follow. They can follow you, letting you do the regular trailblazing while they easily follow and devote their effort into figuring out how and when to jump out in front.