Well, let's break down why people want breeding in the game.
- Enjoyment: Baby dinosaurs are damned cute.
- Aesthetics: Herds look more varied in size and shape, therefore more interesting.
- Immersion: Having a living ecosystem is more engaging and real.
- Convenience: Self-maintaining populations in the face of aging, animal combat and predators.
- Gameplay: Adds slightly more challenge to the population mechanic.
Your suggestion only really adresses the last two points. No cute babies, no improved aesthetics to your park, and having dinosaurs randomly pop out is not immersive at all. Furthermore, if you were to just adress those two points there would be a better way and more immersive way to do it, such as an automation upgrade for hatcheries.
I don't think it's the silliest suggestion of all time, but it's not a very good solution.
I'm still hoping for juvenile dinosaurs at some point. I do believe this may have been planned at some point, because of certain voice lines:
This quote makes NO sense in this game, as next week your Triceratops is going to look exactly the same. As such, I hope it's going to be included somewhere in the years of support this product will be getting.