If you got a cheap skeleton factory, this one pwns pure eggs, it can produce them non-stop.
So, in pure time deck, it loses, but in a death/time deck this one is stronger.
I'm not sure if it is stronger than other time/death decks, but definitely a fun play.
Since hatch is such a strong ability, why not let the upgraded version target enemy creatures too?
The opponent will lose the creature's original ability, but you cannot be sure it won't get something stronger