I'm probably a bad example, but I changed bunch of instructors. I had good relations with all, but as long as I feel that I don't progress sorry, time to move on. Now, NO I do NOT have great expectations for myself and my horse(s), moreover I'm very judgmental towards myself and them, and I do understand progressing is a slow process, BUT the progress should be there (even very slow). So I find it just too expensive to pay for just good relations, you know. So personally I don't see anything wrong/bad with it.
"Life isn't about waiting for the storm to pass: it's about learning to dance in the rain..."
"When we are no longer able to change a situation - we are challenged to change ourselves."
"How people treat you is their karma; how you react is yours."