Most static Buildings are made in High end Programms , some things we see even have been ripped out of Games. But verry difficult to prove as it is mostly only a fragment of those. The OBJ actually is importet into Poser  and reasamled as one static Prop the information of doorframes Doors windows are actually still here , just that the creator instead of importing the OBJ subdivided and reasembled in Poser he merged them into one , It can actually be taken appart in the Material room of poser by saving the materials as Props. And would not be a distingtive work just a Update as Long as the originall product is required to be able to use the Update. It is actually the Major Part of Poser to do so most Products are So called Distinctive works. In the store there is one addon after the other to find one update after an other Just like working as a team On a huuge Project. Restricting these Posibilities would most Likely cause that new great Creators could not integrate ino such a community. We stand still .

It Probably also would Prevent,  Like mentioned by MrSparky Fighting the dark side , rather pushing ( Motivating )the  People to create  then to steal by showing more felibility. and hes just released Product on Content Paradise would of not shown up on a search  right after its release. ( Just a side Joke )

We are Talking here about Legal issues but they result rather into Restriction then to be Productive for an Artist community.( Cant use this Cant Use that ) One allone could of never made Poser the way it is today it has been build hand in hand by many People with many great ideas , and now it seems more and more restricting compairing to the flexibility shown almost a decade ago.

The day every Idea will have been brought out, there will be nothing left to create, rather then to steal other Ideas and resulting, caused by own limitations that people start pointing fingers at each other . 

every healthy management thinks in Decades but not just only in the Present.