Even fractal fate egg is pretty weak. The only decks I've seen using this card are "goofing off" decks, meant to be fun, but not competitive.
I sat down and crunched some numbers on this card and I think the results are relevant to this discussion:
On average when a fate egg hatches:
The quanta cost of the creature made is 5.09
The HP is 3.90
The attack is 3.41
There is a 17.3% chance of getting a rare creature, 14.8% of getting a nymph, 14.8% of getting a dragon.
46% of the time the creature produced is significantly more useful in a rainbow. 4% just slightly more useful in a rainbow.
67% of the time the creature will have a useful ability, 4% a minor ability (web etc)
5% of the time the resulting creature will be useless in a deck not designed for it.
(these are only for the non-upgraded version. I haven't done the math on the upgraded one. Obviously some of my numbers are estimates.)
So basically, in using a fate egg you're delaying your strategy by 1 turn and leaving your creature as an 0/1 Oty snack for 1 turn in order to save yourself a single quanta (on average).
Add to that the fact that it's nearly impossible to design a strategy around random creatures, and that they mess with your quanta use in a rainbow, and there's really no reason why anyone would want to use this card except to goof off.
Needs a buff, badly.