I have edited my comment shortly after posting and added a paragraph. In short: Birds need to develop feathers. How would a dinosaur be bound to its parents?

I have edited my comment shortly after posting and added a paragraph. In short: Birds need to develop feathers. How would a dinosaur be bound to its parents? It's the other way round: hatching from eggs means being able to fend for oneself which means that they don't learn that they have to stick around.