@Jeff - No specific case, just a general problem that I've encountered. I do roll with it, but that doesn't mean I'm not irritated.
@MyxIsMe - I take no issue with your use of the term "cat," but I'm confused by the "scorned women" bit. Are men not allowed to be "scorned?" Do some people, in your case women, not sometimes have the right to feel that way?
But this is a thread about Diplomacy, so I guess I should take off my "complain about casual misogyny" glasses.
Most likely it is, indeed, a new player. In which case they probably would be an easy target, so attacking them would be a good plan. A good player would still talk to their neighbors, even if their plan is to attack them, because they know that not talking at all is a bright red "attack me" flag.
There, in fact, is no sane reason to not talk to a vital neighbor before the first turn. It does nothing but raising suspicion, and it doesn't give you the benefits of talking: securing DMZs/bounces, forging alliances, and gaining information.