"I guess I do not understand why abiogenesis is not spontaneous generation?"
It'd the "spontaneous". Abiogenesis as a hypothesis involves many steps of increasing complexity and not a "poof" - Creation would be a "poof".
Spontaneous Generation has never been disproved, and, by its very nature, can never be.
Pasteur disproved a particular form of it - maggots, mice and mold, etc don't appear in broth or meat if flies, spores, etc, are blocked.