If I recall.....
The original question was "Why do people crop thumbnails for non-nude images?" or something to that effect.
I explained why I do it. 
Others have done the same. 
I don't think anybody said that non-cropped, system generated thumbnails were crap.
I don't have any problem clicking on the sized-down version of an image, if it looks promising, to see it in all its glory.

<-insert words of wisdom here->