> Rejecting someone directly is socially awkward and potentially dangerous.

Very much this. People who've been rejected (male or female) can definitely be vindictive, nasty, and just plain evil. :(

I'm guessing it comes from their feelings of hurt inside from the rejection given. Which (personally) indicates how badly I sucked with interpersonal skills when rejecting people in my younger years. eg I'm pretty direct with people, but had literally no tact when younger. Bad combo. Ugh.

I disagree. The robustness principle (https://en.wikipedia.org/wiki/Robustness_principle) or some permutation of it is used in virtually all communication systems and media channels. The burden is clearly on the sender of the message to be precise, not on the receiver to interpret a noisy message. I can't think of any situation, except for dating, where the burden is placed on the receiver.

You will note the robustness principle applies to "code that sends commands or data to other machines", not people.

It applies to human-to-human communication too. If a politician sends an ambiguous tweet, he or she will be blamed if the message is misunderstood. A marketing campaign can be accused of being racist even if the creators didn't intend it to be. If a worker doesn't understand a managers work orders, it is the managers fault -- not the workers, same thing with a student not understanding a professors lecture and so on.

It's how most communication works in just about all social situations, including dating, but even friends. Rarely does someone you want to be friends with say "Sorry, I don't want to spend time with you as a friend." They're just "busy."