Let me just start by saying, holy crap, man. He wasn't saying that at all. You're putting words in his mouth that he never said, and they're not very nice ones either. Why would you assume that, because he doesn't like bikers on the road, he thinks it's ok to flaunt the law and willfully endanger cyclists? If you really think that's how he feels, you need to seriously examine the concept of human decency yourself.

Now, antagonistic paragraph out of the way, let me tell you why I agree with him. In short: roads are made for cars. You know that, I know that. We can argue the point if you're in the mood for it, but hopefully we can just agree that roads are pretty obviously designed for cars. However, it's quite true that the law also permits cyclists to utilize the roads. Too, good citizens have to obey such laws, and the vast, VAST majority of us do.

Keeping that in mind, let's look at some of your arguments/statements/whatever.

• You say that MK is "simply wrong" because the law doesn't reflect his opinion. That's a load o' processed lunchmeat. Laws are made for all sorts of reasons by all manner of people, and are as fallible as everything else in the world. We obey them because they create order, but that does not mean they are universally right, proper, and correct.
• MK says bikers shouldn't ride where bike-specific infrastructure doesn't exist. You say they often have nowhere better to ride, and act as if that's clear evidence of why they belong on the road. However, it's not. Cyclists don't have to ride at all. Obviously, this is not an attractive option, but it's not the motorist's fault. The lack of proper infrastructure is not reason enough for bicyclist's to needlessly endanger themselves, and other motorists (I'll get to that in a sec).
• You say motorists endanger bikers. This is true, and unfortunate. However, bikers also endanger even the most safety conscious of motorists. While you're riding along on the side of the road, trying to give cars their space, cars are inching around you, moving into the other lane so as not to hit you. Cars in the other lane are moving off onto the shoulder / side of the road trying to avoid the displaced traffic. All of that isdangerous. Maybe traffic shouldn't pass bikers at all, and should just accept that everyone in a car should get to their destination as slow as the biker ahead? Perhaps. But long traffic jams are also dangerous, increasing the risk of rear end collisions, rash actions by unconscionable drivers, etc.
• You say that bikes are a "mode of transportation," and that if everyone rode them, the world would be a better place. You also say this news hasn't reached America yet. And you're right. The vast majority of America is designed for cars. This is bad. The solution, however, is to make America more bike-friendly, not to force bikes into the system where they don't belong. Bikers who insist on riding on roads not designed for them inconvenience everyone (except themselves) and put everyone (including themselves) at higher risk of accident and/or injury.

Anyway. I'll try to wrap up here by saying that I know where you're coming from, and I understand why you're frustrated with inconsiderate drivers. Personally, I'm extremely cautious of cyclists on the road, and it's for that very reason that I wish they'd keep themselves off of it. Does the law say they can be there? Yes it does, which is why I don't yell at them or give them any grief. However, does the law make sense when it inconveniences and endangers dozens of people for the sake of one? Not to me it doesn't. Therefore I agree with MK, and I think your extremely negative response to him (particularly when he worded things fairly nicely, and specifically apologized for any offense) was a bit unjust.