Sorry, what's that got to do with anything? Email is not the same as web browsing. You can't compare the two.
Anyhow, I find images in email incredibly useful - it makes it an extra couple of steps for a lot of things if one has to upload or serve an image and the recipient then has to follow a link to get images.
What area of work are you in? Not big on branding?
I'll have to get some time with Mail.app, does it make no distinction between inline images and attachments either? How about encoded images that are inlined - do they show as attachments too?
I do know that OSX handles vcards very well so I'm kinda surprised it treats them as straight attachments but still don't think that matters so much.
Mail.app handles any attachments as attachments (even inline ones). If images are linked to as part of HTML email it will display them (but not by default due to spam tracking -- you have to click a button to display them), and not count them as attachments though.