Push ups by themselves do not bring me from point A to point B. Pull ups don't get me from point A to point B. However, they do help with the overall running economy. Running helps out running, but there are so many other things that can benefit. I've talked about cross-training and how it helps out, and it's important to realize that in order to make sure you don't get injured, you need that variety.
Today, all I did was push ups because I needed to make sure my legs recovered from the soccer, cycling, and running. Because it's the first few days of getting back into shape since the big race, I needed to make sure I took things slowly. Slowly never hurts you. In fact, it'll help in the long run.
When I focus just on running, it means that the muscles I don't use for running gets weaker, so I need to make sure I do activities that would involve those other muscles. It's nice to do more than one thing and add that variety in your life.
Sometimes, we focus a lot on our specific goals and we sharpen that blade so much that it breaks easily. Balance is the key, and we need to focus not only on our goals, but also on the things around those goals we have made for ourselves. Focus on the whole and not the specific. Take steps to reach your goal with solids steps all the way.