I fully agree that it's a two way street. I've spent 5+ years as a blue belt and stand by my reasons for leaving my last club. Loyalty is a great virtue but we're all our own man and sometimes moving (for unselfish reasons) is the right decision.
I spent 5 years doing Muay Thai with Phraya Pichai becoming an instructor, 3 + years at BTT slough before I came to Oz. I left the club I found here, and had trained at for 2 years, because I felt my investment wasn't being matched and I didn't want my belt to ever be put in doubt because we were required to pay for gradings. That was very important to me and my own personal values were more important than the 2 years I'd spent there.
I'm very happy with my new club and instructor and fully expect he'll be the one who will ultimately award me my black belt.