Goblins are slightly better at rebuilding after a sweeper then Elves are. They also generate card advantage more naturally. I think the biggest difference is Goblin Matron, if Elves had an Elf Matron they'd be superior.
There are many things that Elves are superior at, it's just a archetype that many players miss-use - people haven't settled on a list even though some very good lists float around.
What about Elvish Harbinger? Is almost a Matron, but don't cantrip himself.