Your story sounds like BS.
We are simply not finding many qualified people
You aren't looking very hard then, I know several people who are very good developers, including a Google developer who had to move due to family reasons and simply couldn't stay at Google. I assure you, she was qualified for anything she applied for. So maybe you live in that one place that doesn't have any qualified workers, but since there are people claiming that pretty much everywhere, I call bullshit.
or reject it for reasons other than the salary, such as commute distance.
Another bullshit line. They really went through the entire interview process and THEN decided the commute was too much? That makes no sense at all. You seem to think that these people would waste their time letting you interview them when they never had any intention of taking the offer. That would be pretty stupid and as such makes it hard to believe your version of the story.
We pay $80k-$90k for college graduate starting salaries
Sure you do. Even in the shittiest places to work as far as location and cost of living, you'd have grads beating your door down for the job, moving there from all over the country.
, and a median of $150k for developers with five or more years experience.
Are you in hiring at office int he middle of Manhattan or San Fran? If so, thats not that impressive considering cost of living and experience.
Your entire post just sounds completely unbelievable like its being embellished for you to provide excuses for why you can't hire anyone or pretend that you're even trying.