Some people seem to think that common courtesy is the same all around the world.

Where i come from, it is fine to just say no and that isnt unpolite, its just how it is. Noone actually gets offended by this where i come from. Being on the internet doesnt make me personally feel like being extra polite (and it doesnt make me feel like being less polite).

Wether i take the time to chat with someone over the internet, depends on its purpose. I might just feel like chatting to a strange unknown person, but then again, i tend to chat mostly to people i feel some kind of connection with. This could be the game that we are going to play, coming from the same country or a 3rd thing. Nothing big really, but without that tiny connection that brings us together in some sort of way, i dont care to chat or play for that matter... This actually means i will turn down a "good" game for the sole reason i just dont feel like it.

This in turn also makes me play "worse" games against people i have a greater connection with, simply becourse its more fun.

I think what i am trying to say is, first of, people might not see it the same way you do (Just look at the vote, no straight 6 for any blog). Second, people should always be as happy with a no as with a yes. (well, maybe not entirely, but you get my point i am sure)
Third most people do like to chat, just not to anyone, it has to have at least some degree of meaningfullness.

Dont worry, be happy :o)