> The point is that attachments are needed to make HTML work.

They are not.

MIME headers are helpful for telling MUAs what the content (type and/or disposition) of a message is, but there's nothing from stoping mail clients from just putting "raw" HTML in the body of an e-mail message without MIME.

Yes, obviously you could just email HTML before MIME existed. That's not the point of the discussion at hand.

This is bad logic, and so is your comment upthread, IMHO.