To be fair some modern compiled languages are covered by package managers. For example, Rust and Cargo. Admittedly there are constructs built into the language and design that have made the plausible since early on.
Even above any technical aspect, the most important thing about Cargo's success is that it was the official default from day one. There's hardly any question about how packages should build or dependencies should operate. And indeed, Cargo does encourage (though not require) everything to be built from source, which is probably intentional given Mozilla's stance on OSS.
It has nothing to do with Mozilla, specifically. Binary packages are very tricky. I'm sure Cargo will figure it out and eventually grow support, but this isn't some sort of top-down policy.
It would be kind of difficult to have binary packages unless you have a stable ABI, and Rust doesn't have that yet. If and when it does get a stable ABI, binary packages would at least become a possibility. There are good reasons why Rust didn't want to commit to a stable ABI initially, but perhaps at some point the benefits will outweigh the costs.