That's a very good observation. Bowie often uses these Anthony Newley-like vocal flourishes that make him seem vulnerable, (Wild is the Wind for example) but there is no performer more in control of what is he doing. One reason Judy was such an icon is that we all knew her as Dorothy, which only made her later appearances more poignant. Ziggy has been fascinating and sexy and brilliant but it would be a stretch to call him endearing.