I'd beg to differ.
Developers are generally fluent in a minimal number of languages, on a minimal number of platforms, and can provide support for their product/code only. They often call helpdesk when anything outside of their product malfunctions.
"IT guys" are familiar with multiple scripting languages (batch, vbs, unix shell flavors), multiple operating systems (windows flavors, *nix flavors, mac, and now a dozen different smart phones), and provide support for combinations of all of the above. They call developers when their product alone is malfunctioning.