In soviet times my family lived in apartment with wooden door that opens inside. AFAIK it was common scheme because of fire safety - firefighters was supposed to break doors and save unconscious people.
Right after collapse of Soviet Union and economical shock people began to worry about property safety and began to install additional metal doors which open outside. There was no option because of installation scheme - metal frame was attached from outside.
So, we had two doors at that time - one opens inside and another (anti-thief) opens outside. Yep. Add metal cages on the windows and feel atmosphere of distrust society fell into.
And now everybody around me, including myself, install metal door only in new aparatments, which opens outside. And again, this could be explained and directed by fire safety, but in different manner. But no way you can break these metal doors. With contrete frame only.