I actually think the other way, we let people who join mid race take part in the qualifying, imagine if you will that you, as quite a quick driver, just joined the server. You have a choice, you can start at the back the next race, or you can go out and do a qualifying lap under our concurrent qualifying system and start near the front - your a fast driver, you deserve to be there.
LFS has a history of race position determining your starting grid, we're experimenting with this concurrent qualifying system because we think it offers some advantages, for one - imagine a fast or fastish driver tripping over a backmarker - they then start the next race from the back under normal LFS. With our system they get to resume from their warranted position and try again.
Personally I quite enjoy the new system because I think it puts drivers more or less where they are meant to be and helps to keep things calmer when things go wrong, and prevents the uber leetzor alien crowd from having to charge through the field [not really the same as having a good battle with someone of your own level].