Upload & Sell: Off
I don't consider it unethical. The unencrypted information is in the file unless the poster removed it. If posters want to exclude that information for whatever reason, they can do so.
Besides that, I think it would be the rare case indeed where seeing those settings would allow you to somehow steal/reproduce the photographer's mojo/magic/style/experience. There is a lot more to photography than pushing a button and a lot more than camera model, ISO, shutter speed, etc..
From a practical standpoint here on FM, the EXIF info can be helpful to folks learning about photography and it can also be helpful in answering posters' questions when they forget to list the EXIF settings in the thread.
Still, they're the photographers' images and they can manage the EXIF info as they wish. If they include the EXIF info in a posted image though, I will take that as permission from them for me to look at it.