Remember when the Buddha was newly-awakened, and when persuaded to teach taught his ascetic-friends? He did this because he knew they would be able to understand what he was saying.
I could be wrong, but in what I have read of the suttas, the Buddha never really chases after someone. He makes himself available for teaching and debate and if people don't come, or they don't get it then that is their problem. Some people walked away in anger after talking to the Buddha because of this.
Where compassion comes in is in making the Dhamma freely available, just like the Buddha did. With this you can help any who are able to be helped. But it is important to stress that only those who are "ready to be tamed" will be able to receive the help. Maybe one day those who were not ready to be tamed will be, in another life. But for now it is best for us to concentrate on helping ourselves and those who are really dedicated, and to preserve the dispensation for a long time out of compassion for future generations.
Just my thoughts,
"If beings knew, as I know, the results of giving & sharing, they would not eat without having given, nor would the stain of miserliness overcome their minds. Even if it were their last bite, their last mouthful, they would not eat without having shared."