The purpose of a thought experiment is to make a prediction about a real experiment. The thought experiment is as real as any other abstract object or mental process, and the prediction it makes is as real as a prediction made by any means.
And if believing a belief which is known to be false results is a higher output on your utility function, you have a nonstandard utility function. Rationalists who have radically different utility functions are very dangerous things.
The purpose of a thought experiment is to make a prediction about a real experiment. The thought experiment is as real as any other abstract object or mental process, and the prediction it makes is as real as a prediction made by any means.
And if believing a belief which is known to be false results is a higher output on your utility function, you have a nonstandard utility function. Rationalists who have radically different utility functions are very dangerous things.