Yes, this disappoints me too. I'm going there in a week, am going to try and wangle breaky down in the main restaurant I think.
When HSW first opened, I didn't encounter any problems with taking the complimentary breakfast, for Diamond, in the restaurant, instead of the Executive Lounge. In fact, it seemed optional as to where you had breakfast.
However, one stay I discovered that the charge for the restaurant breakfast had been added to the bill. I managed to have it removed, but was informed that the Diamond benefit breakfast must now be taken in the EL in future.