Something nobody except MicroSoft and Unix ever had, and the prime reason why all other OperatingSystems failed miserably.
What about MacOs? Perhaps that's more of a regiment than an army, especially compared to Windows, but the number of Mac users out there is not insignificant.
Yes, marketing is important. Something engineers often forget. A great idea kept in an ivory tower is just a titillation for its keeper, not something useful to non-specialists. See EngineeringVsMarketing.