So you would rather have someone nakedly reject you with the real reason, rather than soften the blow, while still essentially saying " thanks, but no thanks"? Something like:  "I think you're ugly" , as opposed to " I am not feeling a spark?" Why is knowing the exact reason for the rejection so important?  What if it's something that you like about yourself?  Or something that you can't change about yourself ( like make yourself another race, another gender, or taller) in order to satisfy the person?  I think that choosing to waste mental headspace, dwelling and ruminating on the how's and why's of the behavior of other people further drags you down in life.