By no means do I approve doping.
But the doping is caused by greedy tour organizers, who add way to many mountain passes to collect fees for the tour to pass through a certain town.
Check the schedules, and imagine that any human has to ride across 6 or more mountain passes for more several days in a row. There is no human body able to recuperate overnight.
It is certainly silly, sometimes even dangerous to use performance enhancing substances. But the tour organizers should be blamed.
The careers of the riders who get caught are over. They loose their livelihood. That's punishment enough.
The Tour de France route