Good leaders are highly flexible on most things but very inflexible on a few things.
In fact, it is their flexibility on the majority of issues that makes it possible for them to be inflexible on a few truly important issues.
Where should we be flexible as leaders? On those issues that are a matter of personal preference! Many decisions are not critical to the success of an organization. They could be decided in a variety of ways and still accomplish what needs to be accomplished. The best leaders don't insist on their way or their preferences in these areas. They save their powder for those few areas where they need to be inflexible. Their flexibility on most things gives them the coinage to be inflexible on a few things.
Where should we be inflexible as leaders? On issues that go to the heart of our mission, our culture, our non-negotiables and our central work. These are not areas of preference but of driving the mission of the organization. If you compromise here you lose effectiveness and momentum. Your organization may even go into free fall. On these things a leader must stand firm. Staff will usually give leaders that privilege when they know that on most things their leader is flexible. The fact that they are inflexible on these few issues tells staff it must be important.
Flexibility on most issues allows leaders to be inflexible on the truly important issues.
This is part of the art of negotiation over the long haul of leadership. You give up your preferences on the less important things so that you can realize your preferences on the most important things.
Don't confuse the two!