Sure, the principle doesn't always blindly work. If everyone uses one technology, that can be a single point of failure (one backdoor and we're all doomed). But

Sure, the principle doesn't always blindly work. If everyone uses one technology, that can be a single point of failure (one backdoor and we're all doomed). But think about https for example. It's just plain good for security and anonymity and everyone should use it as much as possible.