Why wouldn't you score anything less than a 7-ring? That doesn't seem right, and I don't think anyone is suggesting that. The square target 10-ring is 1 cm, smaller than the 1/2 in 10 ring on the 4-bull Glock target. The black bull on the Glock target (10, 9 rings) is 1 in. The rings on the Glock target score 10,9,8,7,6,5,4 over a 3.5 in diameter target, which would give substantially higher (and somewhat less arbitrary scores) compared to the square targets, which score 0 outside of 50 mm horizontal or vertical or 66 mm on a diagonal through the center of the bull. In other words, shooting on the diagonal scores better than shooting on horizontal or vertical at the same distance from the center of the target. Somewhat arbitrary where precise scoring is concerned, IMO. And the Glock 4-bull target is, roughly, a half scale 10 meter pistol target, ready to shoot.
As for the 10-meter pistol targets, the 10-ring is 1 cm, and the black (10-7 rings) is 60 mm and the overall target is about 6 in, I think. So at 1/2 scale, the black (10-7 rings) would be 30 mm with the 10-ring roughly the size of a .177 pellet, and the overall target, would be 3 in in diameter with rings scoring 10, 9, 8, ... 1.
So actually, either the Glock target or the half-scaled 10-meter pistol target would be easier, not harder, to score on than the square targets. The concentric rings on both are more accurate for scoring with respect to distance from the center of the bull. And the center black bull is much more appropriate for target shooting with open sights on a pistol.
The intent isn't to make things more complicated. It is to make it easier to aim, shoot and score a match. But heck, I'm easy -- I'll shoot anything.