Ask HN: Why does every entry job require at least 1 year of experience?

I've been trying to find that elusive first job since graduating university in May 2015. Companies usually have two buckets: a regular software engineer position and another one for senior level. The regular one usually states something like 1 - 2 years of professional experience required. Why can't it be 0 - 2 years? How can I get that first year? I have tried applying to the 1 year positions, but then they tell me I lack experience.