What alternatives would you suggest to introducing beginner developers to open source?
For many, getting the smallest update on a big project (although annoying to maintainers) is a huge and very motivating accomplishment.
A bad faith effort like that does nothing for the project OR contributor.
Alternatives to what? Hacktoberfest doesn't actually introduce beginner developers to open source at all. It only acts like a carrot on a stick by offering a T-Shirt for your contributions, anything else is exactly the same regardless of whether Hacktoberfest is there or not. So I guess no alternative needs to be suggested for what you asked for, as Hacktoberfest is pretty much all about providing external motivation. Generally, all contributions that are welcome during Hacktoberfest would be welcome without it as well, so as long as you want to contribute you can, Hacktoberfest being there or not.