Some horses take a very long time to bond. I have had my mare for three years now, and she is finally really coming around in terms of wanting to be near people. My trimmer was here with her apprentice a few days ago, and couldn't believe the change in her. She now comes up to people and puts her head near them for scratches. You still have to be very slow and gentle with her, but she is a totally different horse from the terrified, skittish horse I bought (and who promptly dumped me on the ground twice within the first two weeks).
And I know people say that some horses just don't like to hang around people, and I'm sure that's true. But the sellers said that about my mare - that she was aloof, that she'd never greet you at the gate or be an easy one to catch. I wish they could see her now, lol. She's the easiest one to handle all the ground of my three horses. When I got her, she was extremely head-shy. The only way I could catch her was by cornering her in her stall. Now she puts her nose in the halter for me. I can touch her ears, nose, eyes, mouth, and she doesn't move. She half-closes her eyes in pleasure when I stroke her head. Maybe some horses just don't like people, but maybe the people they met in their lives were jerks too, and they had reason not to like them. Horses are gregarious animals, and can bond with animals of other species. Why not humans? You just have to put in the time and the work to learn to communicate.
How did I create a bond with my mare? I know some here have heard this many times, and are probably tired of hearing it, but I spent months doing an online liberty training course with her and it changed our relationship completely. I spent hours and hours with her, just learning to "speak" her language. Often, people and horses just aren't speaking the same language, and you just need the time it takes to get on the same page. Doing it from the ground, as opposed to doing it in the saddle, puts you in less of a dominating position. Doing it at liberty means the horse doesn't feel trapped. It can leave at any time. What amazed me is that by following each step of this course meticulously, I got a horse that didn't WANT to leave my side. I can ask her to leave, but she always wants to come back. I then did a groundwork course by the same trainer, and same thing - it is amazing.
In terms of bridling, I'm dealing with that now with my new horse. He's only 6 and is still green. When you try to bridle him, he throws his head up in the air and backs up. I was using a bitless bridle because I thought his teeth might be bothering him, but we just got those done so there are no more excuses. I just started using clicker training to get him out of that habit. First I teach him a head down command, and do that for a few sessions. Once it's reliable (he now just puts his nose to the ground as soon as we start a session, lol), I start making the motions I would make to put on a bridle. I put the bridle over his ears and just hold it there (first, I just put it on his forehead). The next step was to put the bit in front of his mouth, but not in it. As soon as he keeps his head still, in a good position (not up in the air), and keeps it there for a few seconds, I click and reward, and we're done. I treat and walk away. I want him to take the bit in his mouth himself, which he's already starting to do. I expect by this time next week he'll be doing it easily. Tiny, tiny steps are key. Don't just bridle him when you want to ride either, put it on, take it off, reward. Or do ground work, hand-walk, etc. You want to stop the session before it gets too hard/frustrating for the horse. Teach him that bridling is not a big deal, and will sometimes result in doing something fun, not just working.