Perhaps the reason many come across as too serious stems from the type of diving they do. For me and those I dive with, the dives we do are conducted in a pretty serious nature. It's not a joke down there when you're nearing 200' in 38F water. There isn't much playing around, and there's not much room for error. Believe it or not, we find this type of diving enjoyable :loopy:. DIR helps eliminate potential problems down there by us being equiped and configured identically with simple top quality gear, and being in the same frame of mind. IMO, DIR cuts out a big portion of the risk pie graph for us.
Though I try to keep my rhetoric civil, I believe I am often guilty from expressing opinions from the point of view of deep cold water wreck diving. DIR divers tend to be more on the technical side of diving, and I suspect their opinions stem from their their point of view. Personally, whether I'm in a wreck at 185' or a warm 60' reef dive, I take the diving pretty seriously as a matter of habit. I always feel as though I have an unbreakable ceiling above my head (can't help it). Most of the recreational divers have a very different point of view as their type of diving probably won't kill them unless they really, really screw up. Technical divers don't have that luxury, and therefore, their brains get wired differently.
There's my take on the subject.
Mike