People who say cats are unfriendly have never taken the time to get to know a cat. While dogs are promiscuous with their affection, cats tend to show affection for a particular person more than others. When you're picked by a cat there's no more friendly, affectionate creature.

That said, I have also known cats that were just friendly to everyone. We used to have a large orange tabby cat in the neighborhood who would just walk up to everyone who walked by and give them head butts. But he was a rare cat.