[dasil003]

People said the same thing about web design too. "Why can't you make your site simple enough to look good in lynx?"

It's a legitimate point.

However the main thing you should realize is that the world doesn't care. You are not paying the bills for these companies, and thus your opinion is moot. HTML email is popular because it works. No amount of nerd rage will make a dent in that. Don't let that stop you from using mutt and aggressively spam flagging anything without a plain text part, but you might save yourself some embarrassment by not farting into the wind over it.