I am speaking for myself, not for all TD's about this subject.
When I became A TD's I did it on a voluntary basis. Depending on what part of the world we come from (me being England) there is a time difference for a lot of us. I personally book Tournaments to fit in with my home life. If it happens that two of us book two tourneys close together...some people can play in one or the other...not everyone is lucky enough to be online all day!!
Sorry had to get that moan out of the way... I do have a life away from iplay... but i still try to make as many tourneys as possible.