> So I'm surprised by how it is almost unanimously assumed in this thread to be bad-tasting.

It's all the after taste, for me. If I sip a diet soda, there's about one full second when I can't tell the difference—then I really can, and the unpleasant-to-me flavor lingers, quite strong, for minutes. Tastes like... I dunno, like I chewed up and swallowed a mild licorice with a thin coating of something that's definitely not food. Maybe some kind of plastic or household cleaning product.