That actually is possible, but you have to manually create the shortcuts.
Check out https://support.mozilla.org/en-US/kb/profile-manager-create-... for docs on the profile manager. Once you've set up the profiles you want, you can launch a specific profile by passing "-P profileNameHere" or "--profile /path/to/profile" to Firefox.
You may also need to pass "--new-instance" or "--no-remote" to force Firefox to launch a new window if another copy of the same Firefox version is already open.
Check out https://support.mozilla.org/en-US/kb/profile-manager-create-... for docs on the profile manager. Once you've set up the profiles you want, you can launch a specific profile by passing "-P profileNameHere" or "--profile /path/to/profile" to Firefox.
You may also need to pass "--new-instance" or "--no-remote" to force Firefox to launch a new window if another copy of the same Firefox version is already open.