Most people feel much more comfortable seeing two women holding hands rather than two men, even if the two men are father and son. The men might be brothers, but still, a large part of society will assume some sort of sexual background behind the simple and beautiful act of sharing the sense of touch. And when it comes to sex, the differences in social acceptance between lesbians and gays is even greater. Why is that?
The article below explains the developmental and educational roots of what is one of the most damaging discriminations made by society: starting already from early childhood, men are deprived of platonic touch. This is robbing men of the emotional security that touch brings to most mammals and particularly primates.
I think the (male) author pretty much nailed it when it comes to a major affliction that is crippling our society. The extent of the damage is not hard to imagine: it fuels emotional insecurity, strengthens stereotypes and, worst of all, poisons human interaction. Who knows how many terrible disagreements would have been avoided if (most) men would not have missed out on vital emotional education?