He didn't try to save Echofrost but, he did it so she wouldn't get punished again. It would be a lie if she came out shinny, sparkly, or as well fed as every other Pegasus. Mountain herd foals are taught to be mean and cold hearted. In the end star always sees the good in everybody and he saw it in him. He did well in protecting Morningleafe as best he could when frostfire captured her. He only wanted best for Morningleafe she was really his whole life.