Actually, the fact that memory safety bugs are more difficult to exploit seems to have increased the rate of vulnerabilities discovered and exploited, and the fact that these are now often higher-level bugs (think insecure feature design bugs rather than low level implementation bugs) - means that once something is discovered, it can often be exploited in a way that is either much more pervasive or far harder to detect.
So no - safer languages won't stop security from being an issue. Secure design, implementation, configuration, and frequent red-teaming exercises are the only way to reduce your risk, and even then - expect to reduce the rate by some %, but never reach zero.
