[arve0]

> if plain text were the only format possible

Hard to enforce? <p>this</p> is text too.

[vaylian]

A few <p>tags</p> in a larger text are ugly but not too bad. Most HTML e-mails are 200 lines of tag soup without any content, then 100 lines of content wrapped in several layers of tags and finally 50 more lines of tag soup without any content.

[paulryanrogers]

Don't forget that the parts you are trying to read are actually text embedded in images