You can get it to launch via spotlight if you create an Automator launcher for it:
Automator.app
Xcode.app
package. So instead you'll have to navigate to it in a separate Finder window and drag it onto the file selector window. It will be at one of the following paths depending on your version of Xcode (oldest to newest):
/Applications/Xcode.app/Contents/Developer/iOS Simulator.app
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Applications/iOS Simulator.app
/Applications/Xcode.app/Contents/Developer/Applications/Simulator.app
iOS Simulator.app
To get a nice icon for the Automator app you just made, you can do the following:
iOS Simulator.app
and choose Get InfoCmd-C
to copy itCmd-V
to paste