It seems to me that the term IIMC is becoming a useful excuse for poor airmanship and non-existant captaincy. In my opinion, this is where the problem lies. And without supervision, there is nothing stopping pilots luanching with this mindset.
If a pilot is within 500 feet of the cloudbase or in visibility of less than 3km, then he really needs to be asking himself why he is there. Sometimes the answer will justify being there in those conditions, but really, for most non-professionals, if you go below those parameters then you are asking for trouble.
IIMC at night is excuseable under certain circumstances, IIMC by day is inexcuseable.