I'd say the bigger nail in the coffin was, ironically, Microsoft's level of security/sandboxing. tl;dr - Snapchat and a lot of other 'killer apps' never were w

I'd say the bigger nail in the coffin was, ironically, Microsoft's level of security/sandboxing. tl;dr - Snapchat and a lot of other 'killer apps' never were written for the platform, and at least some of that was because the apps on Android/iOS did things Microsoft wouldn't let you (I think tracking when the user took a screenshot was one)