Honest answer to your question: Because they have to-do lists a million miles long, and "make an HTML-only version" is often at the very bottom of that list, because it may require high investment while providing few benefits relative to other things on the to-do list. Also, because "giving users control" can mean a million different things… colors, fonts, sizes, dimensions, HTML vs JS, etc.

And if it’s not the same code base, it’ll probably be buggy, because it’s not the UI people normally use.

Server-side rendering of the same UI avoids that hazard, at a much lower cost.

I agree with your point (here, have an upvote), but really, this should be, and already is, a browser option. Easier to do that than to get thousands of web sites to change. I know Safari has "Disable Styles" and "Disable Javascript" tucked away under the "Developer" menu of all things. Firefox has a "No Style" option somewhere in View. Would be better if it were easier to get to or even the default.

Disabling JavaScript is pointless when it also disables the functionality of the website.

It's occurred to me that it may be a market seqmentation tactic. Possibly unintentional.

https://plus.google.com/104092656004159577193/posts/ikRoMcRw...