I've come to the conclusion that people generally don't like change. Oh, superficial change is great; keeps us from getting bored, adds spice to life, etc. But deeper, more fundamental change is frightening and is resisted tooth and nail.
There are good evolutionary reasons why we resist great changes. The risk that such a change will have a negative effect is too big. If it ain't broke, don't fix it
You can see this in all areas of human life, not only aikido.
The above refers to cases when we don't know what the change will bring.
In cases when we do
know that the change would result in something better for us, a different problem arises, one connected with self-esteem. In order to change, we'd have to admit that what we had so far wasn't good enough, that what we were doing was - in a way - wrong. This recognition may feel threatening to many people. Better leave everything as it is and pretend this is exactly what we like best.
And in these cases, I'd expect resistance to change to be correlated with the inability to openly admit to your mistakes in other everyday interactions. Or the reverse: people who accept change easily should be more likely to admit to mistakes.