Hotspot status icon not updated in the panel without an active connection
There seems to be an issue with the system indicator that prevents the orange Hotspot icon to show up in the panel if there's currently not a "main" internet connection available, even though the icon shows up in the popup menu. See the screenshot below:
At first I though this might not be very relevant since you normally wouldn't use a hotspot if you don't an active internet connection to share, but it's true you might be interested on doing such a thing if you want an easy way to connect another device to your computer over Wi-Fi in an environment where there's not any (managed) wireless network available.
Yes, you could create and Ad-hoc network between the computer and that device, but that can be more cumbersome depending on what device you're trying to connect and for which purpose (e.g. an user trying to connect a phone to the user services offered by a computer in such environment might find it easier to simply create a hotspot and connect to it from the phone).