Presumably iTunes is part of their base system image for all workstations, along with Office, Firefox, Adobe Reader, and the like. In other words, a basic set of software to handle standard officework tasks. iTunes is free and IT would probably rather distribute it everywhere than have people trying to install it themselves (or calling the helpdesk to get someone with administrator rights to do it). They then offer additional applications on an as-needed basis to individuals and departments with specific tasks. So the designers who do print publications and the faculty who teach digital art might get the Adobe suite, while people in Facilities who plan construction will get Project. This keeps licensing costs down and simplifies systems according to their uses.