Yes, picking something that was useable 3 years ago to build a product released 2 years ago instead of an alternative that isn't close to being done NOW was surely a massive strategic miscalculation.
By "Mozilla/Servo" I meant "the Mozilla Firefox codebase along with Servo as its research testbed", not just Servo itself (which AFAIK was never intended to be a generally-shippable browser). Could have been clearer, yes.
MS also seem to have a lot more interest in Rust than Google do.