As explained in my reply in a previous thread, support for the hidden * key feature on some networks was added because users requested this support for it. It was added so long ago that I cannot remember which IRC network was using it. If you find out which network still supports it, please let me know. The issues you are experiencing are probably similar to what the other users were experiencing when they asked for the feature to be supported.
At the time, I considered that supporting * as a hidden key made more sense because that feature was being used by default on the IRC network and would have affected all users on all channels on that network, whereas in your example, it would only affect users on a channel where someone specifically set * as a channel key.
Server features like this are the reason I stopped supporting custom features on IRC networks and pushed for the use of numeric 005, to standardize feature support notification for clients across all networks.
