I already do that.
The channel list will show the number of users within the channel, so joining the channel will not provide any additional information. Add to it that large channels already suffer from being larger than what IRC was originally designed for, a robot that joins every time it looks at the list will not likely be welcome unless it also promotes that channel in some way (and even then, some channels don't want any promotion).
Also I think that assuming a larger channel equates to having more important topics is a false assumption. Only the channel operators get to change the topics, so that limits the field of who gets access to topic changing, and that there are many mismanaged channels that have large numbers of users.
IRC messages are routed only to servers that have users within a channel, and servers between the path of servers having users in a channel. It is quite different than newsgroups where every server can get every message, and that any users can "join" a newsgroup at any time after the fact and read the messages. On IRC, what you say is limited in scope to those in the channel at that specific time.
Yes, but that's true of anything on the internet. That doesn't mean users will throw on a happy face and be thankful for someone logging their discussions. Keep in mind that while the IRC protocol does not encrypt communications (neither does the www, pop3, etc), there are SSL-type modifications that are available.
<Disclamer: I'm aware file sharing on IRC is outside the scope of the IRC protocol, but this is a good example of technical vs arrogant> You should see the number of kazza users who give up on IRC after finding out you can't just right click on files to download. It takes a while to learn of all the nuances of IRC.
You mean Dejanews, right? It's definately easier to search throught newsgroups for information. However to participate and post remains fundementally the same. NG programs like Forte Agent have never been all that difficult to use, the hardest part is finding out your local ISP's news group server name :)
I never said there were no support groups in NG's. However, thinking only the person(s) you are talking to on a NG are reading your posts would be quite foolish. Mrs. Henderson (from my previous example) would not have (and should not have) expected her questions to be published elsewhere. While everyone should be aware that your communications on the internet can be intercepted, that is quite different than intercepting communications methodically and posting it on websites, cached forever.