Your preference is likely not similar to that of their typical users. At this point, I'd expect many people receiving text only e-mail from a corporate mailing list or something like that to consider it broken and/or suspicious.

I would personally prefer this too, but there's a lot of people who don't, for good reasons and for bad ones.

I strongly prefer the UI on "Hacker News" to what you get on Twitter or new Reddit, but it's also pretty clear to me most other people don't. I think they ought to, but they don't.