> Given the amount of value open source provides to for-profit companies (with the open source maintainers rarely getting any reciprocal value from the companies that profit off them), why is it so alarming to think that these maintainers might think of a clever idea like this to make a couple thousand bucks?
Because it's not a clever idea at all. First of all, open source software should stay true to what is is, which is free and open. If maintainers really wanted to profit off of this, they should have never made it free or at least offer some sort of pricing model that doesn't affect the essence of the project being open source (e.g., offering paid support), projects like Sidekiq having Sidekiq Pro. Users shouldn't be the one "paying" for open source software through the ads. This is making developers pay for the project indirectly.
Because it's not a clever idea at all. First of all, open source software should stay true to what is is, which is free and open. If maintainers really wanted to profit off of this, they should have never made it free or at least offer some sort of pricing model that doesn't affect the essence of the project being open source (e.g., offering paid support), projects like Sidekiq having Sidekiq Pro. Users shouldn't be the one "paying" for open source software through the ads. This is making developers pay for the project indirectly.
DHH latest keynote from Railsconf 2019 hits the nail in the coffin: https://www.youtube.com/watch?v=VBwWbFpkltg