Well they do have some idea where it is — along the 7th Inmarsat Arc in the Indian Ocean but that extends for 1000 miles.
MH370: Contractor to be given 300 day deadline to find missing Malaysian plane
https://in.news.yahoo.com/mh370-contractor-given-300-day-deadline-missing-malaysian-055955868.html
Are Australian authorities going to dictate the area of search as well???
If so they may be wasting their time.