This letter to the editor of the Australian newspaper The Age, from Brian Cole of Yarragon, a small town in Victoria, ran under the title "What the…":
WHILE I recognise the evolutionary nature of the English language, I listen with increasing despair to the inappropriate use of the word "what".
"What" has an interrogatory sense, that is, it is a word looking for an answer. I have learned to cope with sports commentators using expressions such as "they moved the ball better than what the other team did". But in the second paragraph of The Sunday Age's editorial: "and that their culture was the opposite of what Mr Costello suggested"? No interrogative anywhere to be seen.
There are many ways to improve this phrase. It would be acceptable to simply replace "what" with "that" but nicer usage to write "and that their culture was the opposite of that suggested by Mr Costello".