https://www.bleepingcomputer.com/news/microsoft/microsoft-trying-to-fix-the-windows-10-app-gap-ahead-of-andromeda/

Microsoft last year seemingly abandoned its mobile platform because of a massive app gap and the lack of developer interest in creating apps to fill it. Joe Belfiore, the Corporate Vice President in the Operating Systems Group at Microsoft, stated that Microsoft even paid developers to bring apps to the platform but nothing worked in the company's favor. 

Microsoft clearly doesn't want to make the same mistake twice and launch the highly-anticipated Andromeda without a powerful app ecosystem to support it.