If you find yourself in this position - the position of helping people make changes - one of the things that you may notice is that there is always resistance, but the resistance makes perfect sense. New stuff, is, well, new, and it has to prove itself. Very few of us would jump over a fence without knowing what's on the other side, and rarely would we make that jump just on another person's word; that's just foolhardy. People resist change, for rational reasons, and sometimes the people who handle change the best are the ones who initially resist the most.
I remember when I first started teaching design classes. I usually had one student in each class who challenged everything. He (or she) would ask question after question and look at every corner, every detail to find an inconsistency. Often by the end of the class, that person was one of the biggest proponents of the new ideas. Some people just have to challenge to convince themselves.
I found it funny, though, that most of the time each class had only one vocal critic. But I realized, that people have behavior, but groups have behavior also, and one very characteristic behavior of groups is that if one person voices an opinion, others who share it don't feel that they have to. In some teaching situations, I had no idea how many people had the same concerns; the fact that one person gave them a voice was enough for the group.
Have you ever gone to a meeting and said something radical, something completely out of left field like "all of these problems go back to the fact that we're using vendor X's framework." If you do that, one of the likely outcomes is that someone will speak up and say "surely you don't mean that we should stop what we're doing and replace it?" Sometimes people say this because they assume that what you are saying is going to be misinterpreted and they want to pad the way for the rest of the group. But, that's only what it looks like when you look at it from the perspective of the individual - the person who decided to speak up. If you look at the entire group, it's as if the group itself has an inclination toward or away from a change - and the person who is speaking up is the group's expression of that inclination.
I have no doubt that some people reading this will be "put off" by this perspective. Groups aren't people and if you concentrate on the behavior of groups, there's a danger that you'll spend less time thinking about individuals, but I find myself thinking about both equally. Frankly, I think that we need both perspectives, and it can be disastrous to miss the big picture. This is especially true when helping teams adopt practices.
A very common adoption pattern goes like this. You encounter a group of, say, twenty people and you show them some practice, continuous integration for instance, and immediately the group's opinions spread and polarize a little: you have the people who are eager to do something new, and almost immediately, you have people who see that and they start to adopt a less active stance - "maybe we don't need to change right now", they say, or "maybe this change is too much at once." Each of them will have their own reasons for hesitating, but here's the kicker - I suspect that if you took all of the eager people and put them in their own group, that group would polarize a little also if you gave it a proposal for change.
I suspect that teams seek equilibrium; that it's just a part of human nature; it's the way we act as a crowd. If that's true, I wonder what it means in the context of change work?