This theory mostly does not actually contradict OP’s, except for the assumption that the problem of motivated reasoning would eventually be evolved away.
We can believe that motivated reasoning is caused by a short-term planning algorithm pressuring a long-term planning algorithm into getting what it wants ; and that getting rid of this mechanism would be very costly and so we shouldn’t expect it to disappear any time soon, if at all. Both seem quite plausible to me, and do not preclude one another.
This theory mostly does not actually contradict OP’s, except for the assumption that the problem of motivated reasoning would eventually be evolved away.
We can believe that motivated reasoning is caused by a short-term planning algorithm pressuring a long-term planning algorithm into getting what it wants ; and that getting rid of this mechanism would be very costly and so we shouldn’t expect it to disappear any time soon, if at all. Both seem quite plausible to me, and do not preclude one another.