What was wrong with the system of setting a limit to your hct and otherwise leaving blood doping unchecked? The danger of blood doping is having absurdly thick blood, but it's easy to restrain that with testing. This way the riders can all boost their blood a little, and it will be a ridiculous chore that seemingly needlessly medicalizes the sport, but at least it stops some of the unfairness in the competition, since the testing is easy to bypass.