Arguably, FM already is showing it by disabling those options.
I see
the thread by capink, that's a workable solution (probably--does Kovid's suggestion work in the case of translated plugins?)
But because existing non-English users have saved settings with their translated strings, FM would need to add a schema version (Reading Lists, for example, already has one) and change previously saved settings to 'canonical' strings. Which if done incorrectly could destroy people's settings.
It's a fairly obscure corner case that only came up in testing, not actual use. And FM has been working this long as-is. Plus, my understanding of FM is rather shallow. So while I'll think about it, I'm hesitant to make changes for this.
(If there are users out there that this is a real-world problem for, I'll consider it a lot more seriously.)