I think it's incubment on an instructor to give any student a reality check if they discover that training is jeopardizing their family life or financial well-being. That's pretty much the definition of addiction.
Very good point, Rab. I would like to expand that it is also easy to use "comittment" to aikido as a cover-up for masochism, avoidances of all sorts and escaping from unwanted challenges in the rest of one's life. But everybody needs to draw their own lines and make their own choices, really - and sometimes most of us need somebody to knock us on our heads and point out what we are really doing here...