I get it, all y'all: you don't wish cancer on anyone, and yet, you don't particularly care that Tony Snow's caught a resurgence of it. That, in and of itself, isn't unreasonable.
However, there's no reason to plunk your soapbox up there on the rooftop and scream:
HEY WORLD! I DON'T CARE THAT TONY SNOW HAS CANCER.
There's no reason to say that. However, there are tons of reasons not to (looks bad, unnecessary, etc.). The ultimate one, however, comes down to this: we should never become callous or even apathetic to another's terrible suffering--and a person's previous actions do not mitigate our responsibility to be empathetic.