To be honest, it would be simpler to post this kind of information in the chat window, however, the chat window is quite small, and once you start posting a large volume of information, it's too easy to disrupt what ever is currently going on in chat.
It can be done through handouts as well, you are right. The thought process behind doing something with a MotD, is to make life easier on the GM and not have to repetitively hand something out to every single user.
Think of going up with some other folk on here for a session. These are people who you have never played with, you don't know what to expect, so on and so on. In my opinion, it would be nice to come into something new, seeing a pop up with information on what to expect, a quick greeting by the GM and maybe an intro into the story. Everyone who joins will see this, get the same details and save the GM time by not having to stop what he/she is doing to give the incoming persons the same blanket information that everyone else got.