Okay, even by ISU standards, that's ridiculous. I'm fine with requiring skaters to commit at the time of the GP draw, but skaters cannot control their health and it is ludicrous to punish them for having medical problems. What happens if someone has a serious injury? Or comes down with a very infectious disease? Obviously in such a situation the skater would not compete, and would have bigger things to worry about, but it is inappropriate to punish them as the ISU is trying to.
No bonus is fair, you shouldn't earn money for something you don't do. But making skaters forfeit part of their winnings, which they have earned by their own hard work as a fine - that's just wrong. Athletes should not be compelled to compete if they're sick or injured. Period. It is completely irresponsible for the ISU to push such a policy.
I wonder what happens if the withdrawal is in the middle of an event rather than before.