The EC2 inventory script is an example designed to be customized to your own needs if the stock version does not fit your needs, but for most people it does. I'm also not sure that's the part that deals with stopped hosts :)
Instances that are disabled intentionally don't show up, because you can't talk to them -- which is what most people want.
I assume you may be wanting something different - but I'm not sure why. Sure, they could be put in another group or be given a disabled variable, but that's not appropriate for most people.
Perhaps a good question for ansible-devel list.