HTML as a technology to render plain text obviously isn't getting in the way, because it's plain text. All the features of HTML beyond that get in the way by obscuring the plain text and the information plain text conveys. In my mind, email, or text communication, is not about presentation but is about textual content. If you want to deliver media or style or a visual presentation, it's just not email. I would strongly prefer if it was a plain url or safe attachment in format that doesn't allow any kind of scripting.