The title is misleading, to say the least.

I occasionally suffer from lower back pain. From experience, tight hamstrings seem to be the cause. If I regularly stretch my hamstrings, I am without back problems. If I stop stretching, then, after a few months, I'll suddenly develop severe back pain. It's happened 3 times already, so I'm seeing a pattern.

So I guess my point is: stretching can help in other areas; it just may not help you improve one specific aspect of your performance. It can keep you injury-free.