http://www.amazon.com/The-Way-Men-Jack-Donovan/dp/0985452307
I think it's an interesting distinction that this is not really true of women. Women can get close over various shared interests and activities.
We could have a much deeper discussion on the evolution of society and how the gradual reduction of physical survival difficulty has eroded a lot of the male bonding development that used to exist. But a lot the OP was about difficulty making friends even when people had a lot of things in common, so I was sharing an anecdote on how a shared activity and commitment, even for a mostly trivial hobby, still led to what I considered good friendships.
You may consider bonding through my softball team "play time." I posit that it's better than not bonding at all, but if you really want to dismiss my friendships and suggest the only way to forge lifetime male bonding is to form an underground anarchist militia and make bombs out of soap, I'll take that under consideration.
Based on nothing more than armchair psychology!
Maybe he's trying to gain entertainment.
Just because someone isn't getting X now doesn't mean he doesn't know how to. Maybe he's after Y.
However, 23 years later and I only have contact details for one of the 8, and even though he and I are friends on Facebook we never exchange more than the annual "happy birthday". Back then all 8 of us were in the same hole. Today we have different lives, with little (if anything) in common. Anything we have left for each other belongs to another time, and place.
A softball team is going to provide far more rewarding and, importantly, long-lasting friendships than "shared struggle and purpose".
My hunch is (and excuse me for suggesting this, since I don't know you at all) that if you ever got in touch with any of those 8 again and spent some time with him, you'd be able to reconnect very quickly.
In high school I had two teachers who were involved in the bush war or 'spent time on the border' as it is often referred to, both of them clearly very scarred by their experiences. One of them outright shell shocked.
I'm guessing that there may be some level of self preservation in leaving experiences like that in the past, reconnecting with your life and getting on with it.
I cannot imagine how some kind of reunion would be good for remembrance:
"Do you remember that time when we got a granade and almost died?" "aaah yes... bad times"... "Or what about when corporal Jones was blown into pieces" "aaah yes... that morning we played poker toghether".