I'm pretty sure this must be the case. It allows them to truthfully advertise, "X million players log in per day!!1!" - even if most of those players log in, then log out, and don't actually play at all.
I'm not a fan of log-in rewards, for that reason. I don't want to help SE pad their numbers in that way. (Though, if they did implement this, I probably would log in daily, just as I did in FFXI. I don't feel enormously strongly on the matter; just a vague dislike for the practice.)