I know that we've talked at length about this very subject. It's difficult on both of us in different ways. I've talked at length about this subject with my wife too. As you know, she's a survivor too at the hands of people facilitated by her "mother". She still craves the mother/daughter relationship with a mom, but not with that person. She's now gotten to the point where she understands the difference between craving that relationship with her "mom" and having a mother/daughter relationship. And, in the end, no matter how you look at it, it sucks. It sucks that no matter what you do, how you act or talk, the illusion we have of a sibling relationship with our "brother" will never become reality. It's a tough pill to swallow. Sure, we can say, "Well, I can just go out and find my own family made up of friends." Yes, that's an option, but it's not a true replacement and we know it. There's nothing that will replace that idea we have in our minds about what we expected of a sibling relationship. I think the key is to separate our idea of that relationship from the reality of that relationship. Difficult stuff, indeed.
When I came to this site a few months ago, I was very uncomfortable using the term "brother" with people here. I really had to take a step back and figure out what I didn't like about it and came to the same conclusion you have. From my standpoint, my "brother" is an arrogant, narcissistic asshole and I didn't feel comfortable calling the other men here that. From other's standpoints, I was putting them under the microscope of my illusion. Putting them under the light of what I always expected out of my "brother" just wouldn't be fair to them. I could always find a reason why someone couldn't fill that role. So, I've resigned myself to the fact that the person that sexually abused me for eight years and emotionally and physically abused me for much longer, is not my brother. I've gone to redefine every aspect of "family" over the last couple of months. I don't view the terms associated with these people a birthright anymore. These terms and words have to be earned. Several men here on this site have convinced me that they are worthy of that term. But in the end, the definition of "brother" that I put to these people in my life is MY definition. It is what I think a brother is and how they interact with me. No, there is no one here that is my blood-brother, but I'm okay with that. The men that I use that term with have earned my trust, my friendship and my love in various ways and ultimately, I decided to bestow that term on them. It's my gift to them and to myself. They may not see it as such a gift and that's fine with me. They may not struggle with the term like you and I do, but when I use that term with someone, I have a sense of empowerment and joy.
There are any number of terms that are used here that I'm not completely comfortable with. Definitions are tricky. We have dictionary definitions and we have our own definitions of things. Many here call themselves survivors and I call everyone here survivors out of respect for the work that they've done just to get to this site. I, however, struggle with using the term "survivor" for myself. I know that the dictionary definition would describe me as a survivor, but I can't quite attach it to me yet. I'll get there. The term "brother" and "survivor" are just labels as far as I'm concerned. We read so many posts here about using labels for sexual orientations and abuses and the like, which can all be personal interpretations that have idiosyncrasies that change from person to person. It's okay. We use them as we feel comfortable. It's also okay, good even, for you to express to others how you feel about certain terms. Those who see this and care about you will respect your boundaries of the term and will use something else that portrays the support, love and respect that they have for you. Just know that whatever term is used, the underlying meaning is the same despite what your or my definition of a certain term is.
You aren't going to be held over the fire until you call others here your brothers. Nowhere on the site does it say that you must use this term to refer to others here. Just like you said in your post, it helps for some to use the term to relate to the other survivors here. Good, no great, for them! I can clearly see how it can be good for some. In the other hand, as you know, I can see how it can be a difficult term to use, even painful at times. That's good too. It's good to recognize that and to face it and, if it's in your interest, to overcome the stigma attached to the term and redefine it for yourself into something that can be good for you too.
No matter what I, you or anyone else at the site calls it, we are all bonded by a certain trauma in our lives. We have an understanding of everyone else here on some deeper level than others do. There is an even stronger bond that we have with our support core for whatever reason. I may call it one thing. You can call it what you want. The thing that gets us up in the morning and going throughout the day is the knowledge that we have that those in our support core are there for us in what we need on a daily basis and keep us safe with ourselves. Define that how you will and be good with it.
How about I just call you my Castle and I'll have my own definition of that.