The Firefox-Bing experiment proved that the amount of search engines the "free market" can sustain is one (1). You won't get more without proactive government interference and proper legislation. Meanwhile Firefox loses funding.
"Nibbling at the edges" is what the competition authorities are proposing.
"Nibbling at the edges" is all they can do since that was original proposed method. So they are appealing this particular nibbling at the edges but whole scale, break up Google was not in original remedy so authorities are kind of stuck.