Many GA pilots would be reluctant to challenge an ATC instruction particularly within Controlled Airspace, but this report serves as a useful reminder to both pilots and ATCOs that the pilot is ultimately responsible for the safety of the aircraft and may elect to decline an ATC instruction, if the circumstances justify such a course of action.
Says it all really. The PiC is the only one qualified to juge his own WX conditions. He's also the one who's skin is in danger.