""Its either you can 3D an image perfectly with skill, or not at all.""

OR you simply don't want to - care to - see the need to.  

I also crop photographs.  Not because I lack the ability to get the shot right the first time, but because I prefer to take a larger shot and ponder the crop later.

Some people (as have stated here) actually enjoy the postwork process.    I think the view quoted is entirely too narrow. 

I am:  aka Velocity3d