To have someone actively look for a job for you is indeed not scalable, at least not affordably. What about having people that know you, personal and professionaly tell you about jobs you might like? Do you think they would do a better job than the average recruiter?
That's a nasty list by the way. The thing is most of those issues can be avoided with just a little bit of effort and care...
Why do you think it's not scalable? Think there always has to be a level of attention on an individual level?
What BS are you referring to btw? The usual, "This guy knows Java. He'll probably interested in this Javascript position!"?
Good on you for being so altruistic. Do you think there's any way to leverage that while making it desirable for the developers? Imagine you have great offers that you know would be valuable to the people you found. Would it be spam to share it?