Why do motorcyclists feel they are the shit?

Memorial Day Weekend may be the biggest, most exciting weekend for anyone who owns a motorcycle. Here in the northeast, all bike owners dig out their loud ass bikes for the first good weekend of riding of the year. It's a big deal if you own a motorcycle that can only be used about 3-4 months a year because of the weather.

But, for some reason, these people on the motorcycles feel as though they are the masters of the road.

Perfect example: On Saturday I was driving up to Maine for a nice weekend away. I get to the base of Temple Mountain and I begin to hit the gas so I could make it to the top in a timely fashion. On the way up, there is a passing lane and I begin to pass a group of 3 bikers who are cruising nice and slow, taking in all the sights of NH's back country. The second I pass one of the bikes, the other 2 shift over to the left lane, inches away from my front bumper and slow down, allowing their biker buddy to pass me back.

Is there some sort of rule I don't know about? Are cars not allowed to break up a group of bikes? It was 3 bikes, its not like I was trying to break up one of those 200 man rides.

I was trying to get to Maine for a nice day on the beach, people on motorcycles are way too interested in waving to other bikers and taking in the views, I don't have time for that when the beach awaits. 

Why would bikers risk their lives just so they can bike in a line with no cars in between? This is not Sons Of Anarchy, I did not pose a threat to these 3 middle aged bikers.

Do bikers have rights I don't know about? When did we pass the "bikers can drive like ass clowns" bill?