I maintain a number of open source projects. The projects, resources and the communites use english. However, roughly once a day someone leaves a comment or opens a bug in some other language. It creates extra work and it's an unwelcome distraction for the entire project. The community responds with frustration. But maybe it is as you say, maybe people don't understand that they're reading a machine translation. Browsers should absolutely reverse translate form submissions!
Comments on Your browser lies: the web isn’t written in your native language
> There’s just a small icon in the address field to indicate that the page has been machine-translated.
I'm pretty sure there's more but that's more than enough to realize, at least as long as user/reader isn't completely ignoring most of things on the screen. And unfortunately more often than not they are. And obviously, when Chrome does something wrong Mozilla wants to copy it...
Your idea about fixing form submission on machine-translated pages is a good proposal. I read this article in borked Swedish. I realized it was machine-translated but I can see how people could forget they weren't reading the original.
Recently I heard that to disable auto-translate you just need to add this to your HTML:
<html lang="ru" translate="no">
<meta name="google" content="notranslate">
Alexey, yes that would work, but it puts up a barrier for people who aren't fluent in the original language.
I discussed a limited use of the translate attribute (and the special notranslate class) in an earlier article: https://www.ctrl.blog/entry/html-semantic-improve-machine-translation.html
The problem isn't that the page gets translated, it's that people don't realize they're reading a machine-translated version. My theory is that folks behave differently and have different expectations when they don't realize it's a machine-translation.