You can tell all this revisionist history is written by people who did not experience it. Macbook market share grew among developers because it had a BSD shell and worked well with the web and mobile stacks of the mid- to late-2000's that were built on open source. Among non-developers it was an upsell from the success of other Apple products, especially upselling from the iPhone to the Macbook Air for which there was little hardware competition. User-facing parts of the operating system was not a reason in any of this.