Microsoft focuses on 3 areas for Mobile, not including the youth

Microsoft announced a change in its focus on Mobile and three market segments.

We plan to narrow our focus to three customer segments where we can make unique contributions and where we can differentiate through the combination of our hardware and software. We’ll bring business customers the best management, security and productivity experiences they need; value phone buyers the communications services they want; and Windows fans the flagship devices they’ll love.

In the above there is no mention of the youth market.  Teenagers and college students are some of the most intense mobile users and Microsoft isn't targeting those users. What is missing are the apps that the youth market uses.  Microsoft's strategy is enterprise which many will want office.  Given Office apps are on iOS and Android, the value Microsoft is providing is in management, security and productivity.  Management and Security sound like the rallying cry for Blackberry.

The kids of parents who work for Microsoft have been more and more convincing their parents they want an iPhone, not a Windows phone.  Why?  Because the apps.  Microsoft won the battles of DOS and Windows vs. others with availability of apps.  The losers where OSs like CP/M that couldn't compete with the lack of apps.

Microsoft making layoffs in the summer is turning into an annual event.  Microsoft wrote off $7.8bil and the stock didn't budge.

Microsoft Corp. plans to cut as many as 7,800 jobs and write down about $7.6 billion on its Nokia phone-handset unit, wiping out nearly all of the value of a business it acquired just 14 months ago.
— http://www.bloomberg.com/news/articles/2015-07-08/microsoft-to-cut-7-800-jobs-as-it-restructures-phone-business