I can understand why a corporate intranet would provide a java client for all their employees to use. I can see that being very useful. However I can't see why that implies having to ban everything except the java client.
And you are arguing something that wasn't asked. No one is saying "channel ops should never have such an ability" we are saying WHY should they? Why is it useful? None of the examples you provided really convince me. As I said, why does the fact that a company gives everyone the java chat to use rather than installing mIRC on every machine imply that the guy who installed mIRC himself can't use it? I don't see a connection between the two ideas. It makes no sense to me why you would want a channel that is only allowed to have java users.
Oh and btw you say it's not possible to determine if a client is say mIRC, well it's just as easy to screw up with javachat. I could easily fake the CR java chat. So +j is no more accurate than doing a CTCP version and seeing if it says mIRC. If someone wants to trick CR, they can do it.
