resignation of managing director- enigma stock

Wonder what has caused the Mosaic Managing Director to resign.
Without trying to be unkind, perhaps the resignation?? is a good thing for the company.
I question "resignation" because it seems today's resignation announcement by the company could have also added words of thanks to Mr.Nguyen but not so although that may follow.

Mosaic has been a bad performer on the ASX and perhaps some of this has been due to its inability to convey exactly its future prospects.

I hold but no longer by choice!!