User blog comment:Alemas2005/Administrator Performance Ratings - Two Years-2 months Later (with non-RfA Admins)/@comment-5052737-20160220222936/@comment-5052737-20160221172245

To be honest, that's a problem I've always had, it's that I haven't bothered mentioning it until now.

The difference here is a psychological one. If something happens on chat that needs your attention, and you are in chat, but you are asleep/away, people will try to ping you, which won't work, as you are gone/asleep. It basically generates false hope for users in chat. By being completely offline, though, people simply won't waste their time with pinging you.

Yes, it's a relatively minor thing, but maybe that's why some people are complaining of your activity. Probably it annoys them more seeing you M.I.A. than not being on at all. Just guessing.