Cropping

[Paul mabbott]

This is where I need a 'mystified' smilie! Clearly what I considered the possible loss of quality from cropping (loss of definition) is not what most other people are talking about? Okay, most people are like me and think there's no problem in cropping out redundant background, but what is the objection (by some) to cropping per se?

Given that people mess around with colour balance, with brightness, with sharpness &c: I can see, in certain circumstances, that there might be objection to these because they can produce an image which is untrue but how does cropping do that? Exactly what quality is being lost?