Thanks for the workflow. I made one adjustment: You can install Xcode in another path or install multiple Xcodes if you are a registered developer. You can tell and get the active Xcode env via the "xcode-select" command using the Terminal.app.
I've updated the workflow to use the returned path instead. Enjoy https://www.dropbox.com/s/ygb7me6dl8zw2v9/Launch%20iOS%20Simulator.alfredworkflow