I fail to see how always following a majority of miners no matter what their actions somehow equates to insanity.
Ok, I have a hidden assumption: I assume most miners are also not completely insane.
I have met a fair number of them, and while they are often a little bit crazy (all entrepreneurs are a little bit crazy), I am confident that the vast majority of them are economically rational, and most of them are also meta-rational: they want Bitcoin to succeed. We've seen them demonstrate that meta-rationality when we've had accidental consensus forks.
If you start with the premise that more than half of Bitcoin miners would do something crazy that would either destroy Bitcoin or would be completely unacceptable to you, personally... then maybe you should look for some other system that you might trust more, because Bitcoin's basic security assumption is that a supermajority of miners are 'honest.'