argv0 still makes a great point that if you were to use something like this, which is highly cosmetic rather than actually beneficial, that you would be limiting your script to only newer versions of mIRC. Maybe a scripter wouldn't care about that, but I think most people want to maintain compatibility with older versions as much as possible until it becomes inconvenient such as not being able to use $v1 (something that is very beneficial).
As to your first comment about two commands... based on your thought that one command should do everything, then why bother having two commands at all? If you're going to use that reasoning, then let's just drop one altogether and put everything into one command. Sure, it breaks scripts, but it is better than saying that one command should do everything and the other should do very little. Either two commands should do two different things, or there should be one command.
