Upload & Sell: Off
most of the ones who chose not to show it also post DO NOT COPY or something similar, like someone would really want a low res photo from the web
Bill..... Every photo is not supposed to be a personal teaching tool (EXIF) for inquiring minds. Your above quote is really not accurate outside of the photo learning forums. Even then it's a real stretch to say "most". There are millions of photos in magazines, newspapers, and books that don't mention technical settings. Should we feel cheated because publications didn't see any point to including it? There is endless information on the web that would answer all your specific questions on 'how to'. Those photographers who include "DO NOT COPY", or include a copyright notice have a perfect right to do so. Low res pictures can be lifted and placed on low res websites without permission. Genuine Fractals (now Perfect Resize) program can even make low res pictures into nice prints.
If you rely on other peoples stats so you can duplicate a specific type of picture yourself remember that f2.8, for instance, on a full frame camera is not f2.8 on an APS-C, or on a MFT camera, and certainly not on tiny P&S sensor. ISO 1600 on a full frame is going to look far different on a MFT sensor. DOF, f-stops, noise, etc. are all influenced by sensor size. This is another reason why EXIF depends on the camera you own, not general stats like in the 35mm film days where a format was defined.
The first photograph was made in the 1830s (France). One hundred and sixty some years have passed before EXIF was even available yet photographers managed to learn the basics without that information. EXIF was designed by camera engineers, not photographers. Technical stats will never teach you photography.