X is not faster than well written Y, for all X and Y; that's not a particularly useful comparison though. I've seen a project pick Java over C/C++ because, based on their previous experience, the memory leaks typical of C/C++ codebases were a worse performance problem than any Java overhead.
Well written Java is sure to be slower than well written C/C++.
Happy? ;)
But yes, the point you make, is valid, it is much harder to write C/C++ well, because of the burden of memory management.
So if you lack the time or skilled people, it might make sense to choose Java out of perfomance reasons.
