But do they really? Most those "nicely designed" emails, to be honest, are spam. Either outright spam, like v14g4 and p3n1s pills (modern mail systems deal with those well enough), or only slightly more respectable spam like "you bought in our store once, so now we will hound you forever with ads for our good and services that you don't need anymore".
Among this sea of garbage, there are rare islands of useful updates - like genuine newsletters I subscribed to, or email from my doctor about test results, or reminder from my bank that they are going to deduct that car payment, whether I like it or not, so there better be money there, etc. And of course Amazon shipping notifications! If all those need any HTML, then only the most rudimentary one.
Of course, if you asked a user whether they'd want to get ugly marketing spam or beautiful one, I guess they'd choose the beautiful one. But that's not the right thing to ask.
Among this sea of garbage, there are rare islands of useful updates - like genuine newsletters I subscribed to, or email from my doctor about test results, or reminder from my bank that they are going to deduct that car payment, whether I like it or not, so there better be money there, etc. And of course Amazon shipping notifications! If all those need any HTML, then only the most rudimentary one.
Of course, if you asked a user whether they'd want to get ugly marketing spam or beautiful one, I guess they'd choose the beautiful one. But that's not the right thing to ask.