Why is Play Store still asking for all app permissions on install on Android Marshmallow?
I believe the app has to be made with API 23 (aka Marshmallow's API) and the user has to be on 6.0 Marshmallow or higher for what you want to take effect. However, you can still go into Settings - Apps and change each app's permissions individually, or go into Advanced under Apps (the gear icon) and change them by category. 

Source: Android Developers - Requesting Permissions at Run Time