Louis always tells Rowetta how much he likes her and how he has always liked her but he didn't want to put her through the first round.

If you watch her audition video none of the judges were impressed with her until she started ranting at them. They look totally bored. I'm not a Rowetta fan so this could be bias on my part but my opinion is that she was selected to generate publicity for the show and she has now outlived her usefulness.

Hmmm...The judges were all unanimous in praising her voice, in fact they stated they were putting her through in spite of her 'ranting' because she had such a great voice.
Personally I love her ranting as well .

........I find her ranting rather pathetic and unnecessary - is she on medication

When she sings, she reminds me of some amazing diva. But that image is shattered as soon as she speaks. She then becomes some glorified metal patient. I'm surprised she's got as far as she has to be honest.