then why the goodwill write down?my understanding is that...

then why the goodwill write down?
my understanding is that directors are not confident in future profit at required levels to justify the goodwill.
(its not like the write down is tax deductible or anything, its an accounting entry).

Hence the issue to me is what is future drop in expected future profit that arose because of the goodwill write down.

I have seen this with a number of ASX companies.
They write down good will, say its a non-cash flow item, just an accounting entry. 
But over the next several years their profit under performs.