I see what you mean, and despite what i'm saying they should still put that it.
All rank means is playtime, you quite often see noobs at high ranks, who can play for a long time, just not very well. To intergrate good players with other good players is very difficult, as some people might camp, get a high K/D ratio, but be poor elsewhere. While Gd .v. Gd plyrs would be good, it is very difficult to achieve.