Wouldn't we all?
Its not only FPSC that has such problems - it has been the case with numerous other engines - still is I guess.
I used Lithtech at one time - that had a very good zone system to divide levels up into engine managed rendering zones.
There are some tips around about how to best avoid the probs with doors and windows in FPSC relating to the compiler/engine rendring beyond them.
It not rocket science really you just have to use placement of them wisely. i.e. in areas of high poly counts when using doors try and place a view blocker wall/corridor behind them before a turn to a second door to take you to the next area.
That dont always work as FPSC sometimes renders erratically as so described leaks occur - experience using the software and its quirks will help a great deal here.
But to answer your question - doors are not designed to do so, apparently - why?
Well only the engine developers know the exact answer or reason for that I presume.