Really...WTF?

I'm generally in awe right now. I've gotten over the April Fool's thing (although I secretly hope that karma eventually catches up with that guy), but is there something in the water or do I just trigger some brain pattern in men that turns them into loathsome, rude, or angry creatures?

One example, one of the guys was early to the D&D game last night. Usually this isn't a problem, they can sit down and wait. If you show up 25 minutes early, I'm obviously not ready yet. I was finishing up dinner, getting the kids to bed, the normal routine, which is usually over by the time people arrive. Does he sit? Does he apologize for being early? Does he ask any questions whatsoever? No. This guy proceeds, while I'm in the other room working on the kitchen, moving things around in my family room, mixing together and pitching organized piles of papers on the floor, pushing toys wherever, sitting down on something I had the kids toys on (which he shoved to the floor), picks up my Wii remote and proceeds to play cartoons like spiderman and iron man on Netflix. Really?

Let it sink in a minute. You barely know someone outside of playing a game and this is what you do? WTF?

Another example, I'm hanging out with a semi-acquaintance friend and a group of my friends, and we're talking about the overarching radiation awareness issue in that a lot of people who don't know what they're talking about are causing panic where there need to be more clear heads and general problem solving going on. Instead of making one comment to join the discussion or anything, this guy acquaintance starts yelling that if anyone eats sushi in Japan they'll more or less die of radiation poison no matter where they are in Japan. When he was questioned about why he thought that (we were trying to be polite), he basically said we didn't know anything and he knows it and everyone in his family has an IQ over 180. Really?

Sadly, the conversation only got worse after this...but I'll spare you those details.WTF?

 Less irritating but still Really...WTF category behaviors:
-Guys that complain about not having girlfriends/being alone when they never leave their house and do nothing but make misogynistic comments and whine.
-Guys that posture, acting like the "cool guy" and think that means people will want to get to know them.
-Guys that focus on trying to find romance when they don't have anything figured out for themselves (job, family problems, not having a place to live, car to drive, anything) You really think a girl wants a lazy guy that refuses to get his shit together?

I don't get it. I feel like everyday people find new ways of being rude and taking advantage of people that are genuinely either being generous or kind. They say you need to be the change you want to see in the world. We all know it, so why is it that laziness and complaining override good behavior and general common sense?