The general understanding as I learned getting my masters was that the friendship between two men was, historically, seen as a more noble and valuable kind of love or affection because you didn't "get" anything out of it but the friendship. No, titles, no heir, no political alliances. The value was placed only in the friendship itself since all you got was the other's company

Such isn't to say that some of that love might have gone a bit further than that would have let on back then, but you've got to remember how drastically gender norms have changed, even within the last few decades. As other's have mentioned, some cultures today show male friendship by holding hands or even kissing, it isn't necessarily UNUSUAL unless society seems it so. With literature over 150 years old, some things are obviously going to change