Maybe it's the fact you're getting older, so the people you used to talk to on irc are moving on and doing other things. Neither myself nor anyone I used to associate with on it use it anymore, because we're too busy doing whatever (finishing university, working etc). Things like LJ or forums cater to our 'needs' better, since we're rarely online at the same time.

I dunno what the youngins are doing nowadays. Myspace is too hideous to look at for more than a few seconds, so I'm not really interested in it.