I wish you were right, but C is still the only way to hit all platforms with a good product. It also still rules performance, which does matter in some cases.
Hopefully this won't still be true in 10 years. Hopefully. But I was hopeful about that 10 yers ago.
Ada is about as portable as C, given that both are implemented as gcc frontends.
For performance, the type-safe SPARK Skein implementation (http://www.adacore.com/press/spark-skein/) matches the C implementation, after the optimizer phases in the compiler were matched up.
While doing the translation from C, they even uncovered a bug in the C implementation.
Anecdata, sure, but that's mostly a popularity issue.
Hopefully this won't still be true in 10 years. Hopefully. But I was hopeful about that 10 yers ago.