The point of eggs failing is to increase, by whatever small margin, the rarity of pets.
Yes, it is harder to get pets, and harder to make money off of them. But that is exactly the point. This is not supposed to be easy - and really, it's not all that difficult even with egg failures. Sure, you can wait for your eggs to incubate only to have them fail. But then, that makes it just a bit more special when you do succeed in hatching a pet.
Just try to look at it as another challenge in the game. :)