More accurately, pitchers get hurt. It didn’t take much for Brandon Webb and Jon Garland to go from reliable innings eaters to broken. I wouldn’t really consider Strasburg injury prone anyway. He only has had one significant injury and he came back from it quickly and effectively.
I think if the nationals knew shutting Strasburg down would give them years of health down the line it wouldn’t be a difficult decision. The problem is that no one has figured out how to keep pitchers healthy (and no avoiding the inverted W or ya know M isn’t a magic solution for keeping pitchers healthy or even a proven reason why they get hurt). The Nats couldn’t have been more careful with him his rookie year and his arm gave out anyway. The Nats have a healthy Strasburg now and are in a pennant race and neither of these things is guaranteed in the future. They should keep doing what there is doing, monitoring him closely, keeping his pitch counts reasonable, and let him pitch until he hits some kind of wall and loses effectiveness or gets hurt.