The virtual participation system is great. However, sometimes I want to simulate a contest more realistically, and simply testing system tests becomes a problem as some problem setters tend to have weak pretests.
So here is my solution: virtual participation will only test pretests by default, but you can still turn on system test mode. And when the participation ends, a "Run System Test" button will appear and you can run systests for your own submission, just like how TopCoder works.
Considering the fact that in virtual participation there one can't even see the score one would get in the real contest but can only see ranking base on penalty time, and also that probably I've seen Codeforces blogs similar to your advice here for several times, all of them ignored(?) by the admin, I would say that it is highly unlikely that anything will change. I agree with you, anyway.