Two questions. First, do you think this is a safe generalization for companies whose primary business is software? And second, what portion of the entire job market for programmers is made up of jobs working for software companies?

I'm not sure where you've been interviewing, but from my observation, a newly-minted CS grad is significantly more likely to get an interview for a programming job than an autodidact with a couple of years' experience, at least at most larger companies. If you don't get an interview, it's tough to get hired.

It's worth remembering that someone has to pick your resume from the pile before you ever get in the door to have your intelligence tested. For a recruiter or HR person without a strong technical background, the name of an institution where an applicant earned their degree jumps out a lot more immediately than tidbits like "taught myself Ruby and wrote a point-of-sale system" or "built RPC bridge between Java and Common Lisp for desktop GUI apps."

Now, if the folks screening resumes are themselves hackers, your screening process will make selections based on much more useful criteria.