Mozilla's Gecko team is incredibly interested in both uncompromising performance and strong security. Rust is the first language in industry to offer the zero-overhead abstractions of C++ while retaining memory safety (with the exception of perhaps Ada, which has never taken off outside the government sector).
You seem remarkably uninformed as to what Rust's goals are. Allow me to enlighten: reliability is a big, big deal to the Rust developers. Security is a big, big deal to the Rust developers. Speed is a big, big deal to the Rust developers. Memory efficiency is a big, big deal to the Rust developers.
As for your mistaken assertion that such efforts at memory safety are unnecessary in real-world code:
https://groups.google.com/forum/#!msg/mozilla.dev.servo/ufJM...
>>> * Do we have data showing how many security bugs we could be avoiding in
>>> Servo in comparison to Gecko? Is the security benefit truly as valuable
>>> if expected performance benefits don't pan out?
>>
>> We've been talking to some members of the security team (Jesse, Brian). In
>> general the main class of security vulnerabilities that Rust offers a layer
>> of defense against is memory safety problems in layout, rendering, and
>> compositing code. Use-after-free is the big one here, but there are others.
>> I'm not in the sg so I can't run the numbers myself, but I am told this
>> constitutes a large class of security vulnerabilities.
>>
>
>A quick scan suggests that all 34 sec-critical bugs filed against Web Audio
>so far are either buffer overflows (array-access-out-of-bounds, basically)
>or use-after-free. In many cases the underlying bug is something quite
>different, sometimes integer overflows.
>
There are 4 sec-high bugs --- DOS with a null-pointer-deref, and a few bugs
reading uninitialized memory. The latter would be prevented by Rust, and
the former would be mitigated to the extent Servo uses the fine-grained
isolation Rust offers.
There are no sec-low bugs.
Web Audio is an example of a feature which has very little security impact
of its own. Its security impact is entirely due to bugs where violation of
language rules can trigger arbitrary behavior. Rust prevents such bugs. A
lot of Web features are in this category.
TL;DR: Firefox's Web Audio component, which in theory ought to have practically zero attack surface, contained at least 34 critical and exploitable security vulnerabilities. All of these were a result of the lack of safety afforded by C++. Rust would have made these vulnerabilities impossible.
