Much of the reason why many people hate HTML is that it is frequently used for emailed adverts. A lot of spam is in HTML because it looks attractive at first, until you realize what it is. Too many email providers have HTML as the default format, and this is particularly annoying to people who do not know what it is our how to switch it off.
However, there are some forms of email where HTML is preferred, especially newsletters and e-courses provided by professional internet marketers who know how to use HTML properly. A newsletter looks better, more professional and is easier to read and follow if it is formatted properly. It is better to offer your email list an offer that is hyperlinked to your sales page, or even directly to an affiliate merchant’s page, rather than publish the full URL that clearly shows your affiliate references.
It’s easy enough for those that know, how to check the source code and find out the same information, but it is just an added piece of security and also makes the whole mailing look neater without these URLs, some of which can be very long and look practically meaningless to a recipient reading the message.
If you are in the habit of sending HTML emails, however, you should also provide the option of plain text. Most of the good commercial email providers send a plain text version with the HTML version. The reason that many people prefer plain text is for simplicity. Many feel that if you want to provide a page with all the bells and whistles attached, then a simple link to a web page with the same information would be easier and quicker.