This comment confuses me so much.
Mozilla absolutely has been helping to keep web standards in check. Maybe not to the degree that you would like, but if it were up to Google, we'd all have some ancient under-specified version of SQLite and LLVM encoded in web standards, as they tried to just drop those in for database storage and NaCL.
Mozilla pushed back on those, demanding documented standards that could have independent implementations.
WASM is the cross-browser, much better specified alternative to NaCL.
Formal standards in an executable language are by far the exception rather than the norm. For something with as big a surface area as web browsers, I'm sure they would cost an ungodly amount of time and money to complete. And while you may prefer to reduce the surface area to deal with this, no one wants to break compatibility with existing sites.
I'm a bit puzzled by what you actually want. Mozilla did scale back its investment in Rust, WASM, and the experimental browser engine Servo, to focus more on its core browser, in the recent round of layoffs. But the existing investment has paid off; a number of projects that started off in Servo, and were written in Rust, like the CSS parser and Webrender, are now part of Firefox, providing safe, parallel styling and GPU rendering. WASM is widely supported across browsers, providing an efficient compilation target which is much better specified and easier to work with than JavaScript as a compilation target, or something like NaCL.
And some of the other efforts, like Rust and WASM, have now achieved sufficient industry adoption that other companies are picking up the slack; Amazon, Microsoft, Google, Fastly, and others are all hiring and paying people to work on Rust and WASM full time.
It seems that other than funding Thunderbird development, Mozilla is doing what you want, but you somehow still seem unhappy with it. Why is that?