I would imagine there's many features that mIRC currently supports that could be accomplished via COM Objects, but Khaled still implemented commands/identifiers into mIRC to perform those tasks. Why not Registry manipulation? Just because it can be done via other methods is not a good excuse why there shouldn't be commands and identifiers to manipulate the registry. You must keep in mind that not everyone knows how to work with COM Objects, and probably doesn't care too either!
Obviously you haven't read the third locked post in this forum:
Here's a quote from the post:
"Improve on suggestions or show the poster why his suggestion just wouldn't work or make sense ("you can script it" is not a valuable response).
Remember that people come in here looking to pitch an idea to Khaled, not for other forum members to shoot ideas down."
That's what you're doing, shooting down my idea.