Agree, that could be possible but as we got some email for an issue, we do not get any link for the image. we directly get the image inside email. same way it would be nice if we have. otherwise we have so many sites to host images.
And what happens when someone puts an image in that's not safe for work? Do you really want to open up an email that some "wit" has decided to put a picture of genitalia in thinking it's clever? This has been debated and the downsides are too many. If you choose to click the image link to open it, you do so of your own volition.
*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington