The real reason you can't hire developers....
I'm going to say it because it seems no one else is.  I apologize ahead of time for my brutal honesty.You need to consider the possibility that you're not as competent as you believe yourself to be.  Dunning-Kruger[0] is real, and your post doesn't demonstrate the self-awareness the best developers seem to possess.Your writing is sprinkled with emoticons and rife with reduplicated punctuation, both of which (especially the exclamation points) are common signs of immaturity.  Reading this diatribe--and assuming your 50 emails were written similarly--I am forced to accept one of two conclusions: either you're not aware that your writing is unprofessional, or you're aware that it's unprofessional and unconcerned.  Either option does not reflect well on you.  To put it bluntly, if I received an email from you in this style, I would archive it without response, assuming it was from someone who lacked the requisite introspective capability I expect from the people I want to work with.I found it particularly telling that you claim that all five of your phone screens went "very well" but marveled that only three companies tried to set up an onsite interview with you.  Unless both the two companies that stopped at the phone screen simultaneously filled the position immediately after your phone screen, you really need to recognize that at least those two phone screens did not go well.  I do interviews at a large Internet company, and one of my goals--one of the goals that I've been trained to seek--is to ensure that the candidate, no matter how bad, walks away from the interview feeling good about himself/herself and the company.  If you're doing really poorly in an interview, I'll toss you some easier questions than I normally give, because I have all the information I need, and I don't want you to have a negative experience with my company.  You may have felt good about the phone screens, but the most likely explanation for the two companies that didn't bring you onsite is that you didn't actually do well enough to justify additional interviews.  These people want to hire someone, and if you were someone they wanted to hire, they certainly would have continued to interview you.I think your experiment was less valid than you think it was because you're less competent than you think you are.EDIT: I should add that whatever the case, whether I'm right or wrong about you, the best response to the situation you're in is to seek to improve yourself, not to embark on a quixotic venture to change others.  Read CS theory books, create and modify open source projects, solve fun programming puzzles: sharpen your skills and--no matter what your level of competency--your prospects will improve.[0] http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect