The problem here with "apps" Is that Microsoft does not have any way to certify those "Applications" for now, and certify that the provider is "Secure" and a "Trustable" source, in a major concern. This can lead to, many unexpected scenarios. From there what can be offered as Realistic Help Desk on the forum need to be limited.
We can't say either there is no relation between the "Apps Store" and a Windows Platform for example, but the current "Software assurance" have limitation and need to be respected. Otherwise and in others words, it can clearly harm your PC or Tablet, Android Device, Phone etc.
Microsoft have to be strict on that policies because it's more frequent to have Web Apps Designer that can insert keylogger and so on.
I hope this informations will help you to understand.
I wish you a great evening,
Regards, Armand B.