The point is that there is no motive for it.
You really don't think there are some powerful people out there that might have a motive to destroy a decentralized currency? I would say that's a bit naive. The larger Bitcoin grows, the more motive these people have.
Are you implying that Tycho is some kind of government agent who planned this from the very beginning, and is just waiting to hit 50% so he can take down the entire network?
No. If I meant Tycho, I would have said Tycho. I think Tycho is OK (besides the fact that he doesn't limit his pool size on his own). I said powerful people. Governments. Central bankers. People that run the world and like it that way. Why bother building a bunch of computers to harm Bitcoin when the work has already been done for you and all you need to do is use force to take control of it.
Mine where you want. You've already made up your mind, no amount of information is going to change that.