Don't get me wrong though: I think Hacktoberfest is a terrible idea in
that focusses on short-term fly-by contributing rather than fostering
the long term commitments that all open source projects desperately need.
I understand the frustration and indeed there needs to be a solution for engaging long-term contributors.
I think it's true that not everyone participating will end up as long term contributors, but this is a general problem, and we see the same issue with sprints at conferences as well. Perhaps only a small percentage of participants do end up being long term contributors.
I think it's unfair to say that sprints/hacktoberfest is bad because we don't end up with long term commitments. It's not our place to judge people's motivation into contributing to OS projects. Some people have never been exposed to OS before, maybe they just want to try it out and see if it's something they want to do long term. Events like sprints and hacktoberfest lets them experiment and to try contributing. It's ok if most end up not wanting to continue. So maybe hacktoberfest is bad for maintainers in general, as we get very little out of it, but it can be good to some others. I think we should not limit ourselves into saying "only serious/long term contributions are allowed here".