This is definitely a half baked observation of a "pain point".

I was snapping some images from the web, with both the "Snag-It" tool and right-click Save As.

These were JPEGs

But I wanted to cite, within the image, where I got it from on the greater web.  I wanted to keep the provenance.  I wanted to add metadata to this thing, not create some tiny TXT file to write out the data and sit it next to.

I couldn't think of a tool to add personally relevant metadata to non text files, that I could view on my machine.  Notes for me.   (And there are a lot of practical issues about why this is the case, but…)

Why is it my perception that metadata authorship only for the realm of experts?

(excluding websites that support tagging)

…And granted this is probably a nearly Operating System level issue, but it may tie into Ben's observations about packaging metadata.