In XCode6, the list of simulators are different from the traditional way. It has simulators as iPhone 4s, iPhone 5, iPhone 6, iPad Retina etc for each iOS version. In case if the XCode supports 3 iOS versions, then it will show almost 23 simulators.
Having them to show all 23 simulators in one list will be confusing to the user. So, we need to categorize (through multi level menu) the simulators based on the version, similar to Simulator device menu.