I agree with this, but to be clear, the "summer interns hypothesis" is not "summer interns go around breaking stuff," it's "the existing population of engineers

I agree with this, but to be clear, the "summer interns hypothesis" is not "summer interns go around breaking stuff," it's "the existing population of engineers has finite resources, and when the interns and new grads show up, a lot of those resources go toward onboarding/mentoring the new people, so other stuff gets less attention."