Windows Phone 8 and apps

Tom Warren writes a good summary of the recent Microsoft Build event in Seattle. The following sentence, where he compares the improvements of Windows Phone 8 to Windows Phone 7 is worth noting:

Microsoft launched Windows Phone [7] with a marketing effort designed to minimize the importance of apps — with ads about smartphone addicts — but it now finds itself reversing on that message and focusing on apps with Windows Phone 8.

It seems Microsoft originally bet against apps with Windows Phone1. Now they've reversed on their position. Whilst it's good that their position has switched, I can't help but ask why the software giant didn't realise the importance of apps earlier.

1: Either that, or they majorly downplayed the importance of apps due to the lack available for their new platform.