The Henri Cartier-Bresson philosophy? I used to believe that crap too. Then I saw how Walker Evans cropped many of his photos. Some of his large format negatives he cropped with scissors. I just finished reading a book on Michael Schmidt and there were examples of how he cropped sections of photos, making more than one photograph from one negative. Many of the greatest photographers of the past cropped their photos and many of the best photographers of today crop their photos. While many a photo has been ruined by editors and their cropping tools, more have been improved by knowledgeable photographers working with their images, cropping to make them better.
So what if image quality declines with cropping. If it makes the photo better, no one will notice the image quality. Or care. Only those who get knots in their pixel panties over image quality pay attention to such things.