The lore says that a dragon should choose a worthy human to share his heart with, and a proper choice defines if he'll go to the starts or vanish when he dies. In original movie, Draco feels guilty because he made a bad choice, he saw the prince was bad but believed his heart would make him a good person. So, Draco was an exception.

I understand that this movie plot required the sharing to happen early so that Gareth would have time to make his choices between good and bad and these choices save Drago. But still, Drago had just arrived and immediately shared his heart with the first person who saved an egg. Which he did for greed!

Ok, I had to accept it for the proposed plot to work. But then they start killing an egg after another! With even Drago suggesting it!! If these eggs aren't worth much, why did he value so much saving one?!

And then take an egg and share the fetus's heart! Wasn't a dragon meant to make his choice?! Wasn't sharing the heart meant to be a special event? Now we'll have a dragon being born without the chance to choose who to share with.

In this movie they not only devalue eggs lives, but also make mundane the sharing of dragon hearts. It's a shame for the franchise.