If you're using a bouncer, it's trivial to set it up to change your nickname when you're not there. That clearly communicates that you're not present, but that you will respond in time.
All the other points are kind of silly. You can say the exact same thing about email, or Slack/Hipchat, or SMS.
> There are many reasons why one might consider this unfortunate—no opportunity to be truly away, frequent interruptions, an inflated sense of urgency, and a powerful sense of "oh noes, I'm missing what's happening on IRC!!!!"
All the other points are kind of silly. You can say the exact same thing about email, or Slack/Hipchat, or SMS.
> There are many reasons why one might consider this unfortunate—no opportunity to be truly away, frequent interruptions, an inflated sense of urgency, and a powerful sense of "oh noes, I'm missing what's happening on IRC!!!!"