I am a F/O in a company where I cannot all Reject!!! (737) Insane
Why is that policy insane? In fact it makes cold hard commonsense.
Your responsibility as second in command is to advise the pilot in command of the problem and in turn he is entirely responsible for the decision to reject or continue. Any captain who blindly aborts a take off on a "reject" call from the first officer is either supremely over-confident of his first officers uncanny ability to instantly diagnose a serious event during take off -or - he is incompetent. Probably both..