I found one: my Mobile browser doesn't show the alt-text. But that's a limitation of that browser, and it still works just like it works now.
Fair enough, I stand corrected. I suppose we could do a combination of your suggestion and what Jet is suggesting, at least temporarily. Use the alt-text and if you decide to embed your image also post the link as a footnote to the image (this way nobody will miss it for any reason); unless, of course, I am missing another fundamental flaw and stand corrected.