A lot more. Though in proportion to the number of people that have Internet access these days the market share enjoyed by IRC networks has nosedived considerably.
It depends what market you're talking about. IRC was never in the "instant messaging" market, IMO. If anything, it's closer to a forum/mailing list than it is IM. As far as "forums" go, IRC is a pretty strong competitor, and always has been.
IRC has always been a niche market (just like forums / mailing lists). You can't judge niche markets by market penetration, because that isn't their goal. It was never IRC's purpose to solve mass market issues like IM, email, geo-social-interaction, etc.
For what it is, IRC has grown. For what it isn't, sure, it's done poorly, but that's because it's not meant to do well in those sectors. I suppose this part is subjective. Some think IRC is meant to evolve to become the next FB chat; I think IRC is fine where it is.
I think IRC would have done a lot better if it caught up with the times a bit and more people got along with others. I have lost count of the number of IRC networks I know of that have become fragmented or even closed down due to petty squabbles and personality clashes.
As far as personal issues goes, this isn't specific to IRC. Many a-forum have gone down for the same reason, and same with mailing lists. Politics are much more disruptive for smaller communities, in general. Same with DDoS'es. Note that I am agreeing that this can be disruptive, and sure, if we got along better that would be a solution-- the reality, however, is that even on larger sites, there are politics wars, DDoSing and other disruptive behaviours. The difference is that there is less of an impact when you're dealing with tens of millions of users versus tens of thousands. You don't think twitter has a spam problem? You don't think FB get's DoS'd? You don't think there is infighting in some of those new social startups? I beg to differ. They just are able to hide it a little better. Niche markets are usually much more vulnerable to that kind of a thing, but it doesn't mean there are *more* assholes on IRC per capita.
