The reason we help here is to help those who have read the help file and don't understand something. True people don't always read it, but that's the theory. The help file is very useful for trying to remember something, or looking up something you can use to have X affect on a script. I think the help file is meant to be more of a guide than to answer every single question possible.
There are so many external help pages to read, a lot are on this website - the http://www.mirc.co.uk/help
directory has some good documents, the forum's search feature, the mIRC FAQ etc..
I'm not going to deny that the help file could do with improvement, and I think it's a good idea that it be reviewed. However, along with developing mIRC, keeping up with (other) feature suggestions/bug reports, dealing with hundreds of emails and real life, re-doing, or even updating the help file, would be a huge task.
Perhaps it would be an idea to post here every section of the help file you can think of that needs improving, remembering to be objective as possible - just because YOU think it would be nicer/neater/cleaner/whatever to use a certain format in a scripting example doesn't mean everyone else does. I can't see a problem with either posting here or emailing Khaled with your ideas for the help file, I'm sure he appreciates the help he receives as dealing with mIRC alone would be an impossible task.
So basically, as Soul_Eater said, both advanced and new users should perhaps be more specific in what they don't understand - some parts of the help file are very easy to understand (i.e. I think the Agents help file is very simple, coupled with this page
), so saying the help file is "not helpful at all" is a bit unfair. It is a very good resource, and I don't wish to put it down.