You could apply the same argument to webpages. I think HTML e-mail is a complete mess right now, but allowing some degree of e-mail styling does go a long way in helping users understand what the e-mail is trying to convey.
Something as simple as laying out tabluar data in a table is extremely hard to pull off effectively with a plain-text e-mail.
Something as simple as laying out tabluar data in a table is extremely hard to pull off effectively with a plain-text e-mail.