From thread "Windows 10 Mobile build 10549! How do you like it?":
This is really annoying me too. I have no idea of what should be the benefit of leaving apps open on their home screen when returning from them using the back button. Background tasks should not be the point, as this works without the need to keep the apps visible. If I want to keep the app content open, I may simply use the Windows button to return to start screen and open another app. The way it is handled now, all the apps just eat up system ressources - or at least fill up the task view - unless I clean up manually. It takes some steps to do so including long press back button (longer than Windows button to bring down the screen), there is not even a "close all" button.
The behavior was already there in WP8.1 for some apps like Skype and Lumia Camera. I think they got some special rights to do so. The benefit in Lumia Camera was, that it kept its settings until really closing it. However, I found that it already lead to inconsistent user experience and now it seems to become default unfortunately.
Only thing I still miss is closing apps by using the back button. Most apps stay active in the background when using the back button and after a while performance drops because there are too many apps open. Having to close them manually by using task view everytime gets somewhat annoying.
This is really annoying me too. I have no idea of what should be the benefit of leaving apps open on their home screen when returning from them using the back button. Background tasks should not be the point, as this works without the need to keep the apps visible. If I want to keep the app content open, I may simply use the Windows button to return to start screen and open another app. The way it is handled now, all the apps just eat up system ressources - or at least fill up the task view - unless I clean up manually. It takes some steps to do so including long press back button (longer than Windows button to bring down the screen), there is not even a "close all" button.
The behavior was already there in WP8.1 for some apps like Skype and Lumia Camera. I think they got some special rights to do so. The benefit in Lumia Camera was, that it kept its settings until really closing it. However, I found that it already lead to inconsistent user experience and now it seems to become default unfortunately.