I was thinking the exact opposite. Many organizations (especially the govt) rely on SSL proxies like BlueCoat that effectively hijack SSL traffic with on the f

I was thinking the exact opposite. Many organizations (especially the govt) rely on SSL proxies like BlueCoat that effectively hijack SSL traffic with on the fly generated SSL certs from a trusted organizational CA, in order to inspect/filter outbound data. 'Pinning' would totally destroy this capability if organizational CA's couldn't override it.