Have now worked out what it is that I dislike about the Ethnicity, Country selctors; aside fromt eh word Ethnicity. Thunderously obvious having thought about it.
My focus is on the search box but using those filters requires divererting my eye gaze from the top left of the form to the bottom right of the form and then cascade through the +s of the filters to reach the desired filter value. Makes for what in sign language communities we call "eye strain" or more recently the Wimbledon swivel. Being used to search ssystem (including SQL) I always prefer to type searches like this
TITLE=German and Ethnicity=German not Country=German
I know it is possible after opening the cascades it is possible to invert a fitlter but that then makes for additional eye strain as one must now suddenly return the gaze from the bottom right to the top left before getting a list of the matching books/recipes.