By definition it is cropping. Nikon calls one of the crop aspect ratios “DX crop” for example. If you select one of the crop modes prior to capturing an image you are making a decision to crop a portion of the full frame sized sensor.
If my intention was to frame loose and/or gain a greater working distance, I would choose to shoot full frame and crop in post rather than crop in camera for the reasons I mentioned in my original post. In my opinion, a shooter using this crop mode to meet requirements of a competition is not showcasing superior skill while meeting the requirements. The photographer is simply choosing a different approach or gaming the rules to achieve a perceived advantage. Not that I care to enter such a competition and have no dog in the fight.
The only reason I would choose DX or other aspect ratio crop options is to increase shutter speed while shooting down field sports where I always need to crop anyway before submitting images for publication or I need card space and a similar fast action scenario where I will need to crop. I shoot a D3S UW and D4s for sports and neither shutter speed or card space is ever an issue so I never use DX crop.
Just to clarify: Choosing DX mode in a, for example, D800, BEFORE the shot is not cropping IMO. Cropping in the camera AFTER the shot is the same as cropping at home