I think it's the best thing about Fallout 4, in fact. I imagine part of this is due to the fact I was really invested in the Lyons Brotherhood and actually interested in what happened to it after the events of Fallout 3. I found the idea of Elder Lyons trying to make the reforms which Veronica wanted to make and ending up with a fascist conquest-minded organization to be a really interesting twist on the old formula. Also, the fact a kinder interpretation of the group is that it's actually the new canon version of the Midwest brotherhood of Steel since they existed but clearly didn't become the group they had the potential to be. Arthur Maxson is also a character which possesses things which the other characters in the game lack in terms of backstory, gravitas, a cool look, and also a significant role in the story. There's some flaws in the story because we never really got a reason why he's such a genocidal racist but you can certainly believe people would follow him. Players also have an interesting mystery with whether or not he's a puppet of the WCBoS or whether he's his own man or some combination of the two. I think the game could have been significantly improved if they'd dialed down the presence of the two least interesting factions (Railroad and Minutemen) to focus on a Gray and Gray Morality between the Institute and the Brotherhood of Steel with the rest of the Commonwealth caught in the middle. You could actually have the war going on full-stop by the start of the game as well like the one in the Mojave. I also don't think you actually need the "destroy Synths" plot and can just have the BoS out to take the Institute's technology because that's what the BOS does.