My best guess is that is due to HR and mangement wanting to cover their ass when making hiring decisions. If a candidate is hired and they don't do well they can appeal to the authority of the degree the candidate had to make their decision seem rational.
I went straight from high school to a very entry level web development job. I didn't have any chance at getting a job at a larger company but small web shops provided an opportunity for me since I could be hired at a low wage and the owner of the company was the one hiring me.
Now I am grateful to have moved up the ladder over 10 years time and I have a much higher paying job and no student debt.
The degree opens doors, and it makes management people feel that it's a good predictor of outcomes but in my opinion from hiring, we found Curiosity, Ability to Learn, Ability to Listen to be the three best predictors of good outcomes.
For as long as I've been on tech interview loops, it's not HR but the manager who makes the call with (sometimes strong) advice from the interviewers. Maybe the recruiters don't take the self-taught as seriously as they should …
I went straight from high school to a very entry level web development job. I didn't have any chance at getting a job at a larger company but small web shops provided an opportunity for me since I could be hired at a low wage and the owner of the company was the one hiring me.
Now I am grateful to have moved up the ladder over 10 years time and I have a much higher paying job and no student debt.