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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.'
Miners not being crazy does not mean they are infallible. They may misjudge the market and change their minds about what is the most reasonable action based on new information. Their commitment to one fork or another is very dynamic, and is a huge assumption missing. They may overestimate their influence, support of the economy. Other factors may come into play that no one thought of, and they can revert back at any point.
Labeling things as insane or crazy is not productive.
>because Bitcoin's basic security assumption is that a supermajority of miners are 'honest.'
Only if you rely on SPV.