Living together commitment issues

My boyfriend and I have been together for a year and a half. Recently, I had a job offer that would require me to move away. My boyfriend was very supportive and wanted to move with hence we will be living together. I decided not to take the job because of personal reasons. However, it left the question of how can my boyfriend be not ready to step to move with me where we live not but is able to make that commitment in a completely different state. What are your thoughts?