Having technical skills doesn't necessarily mean that someone is smart, especially when it comes naturally to them.
Sure it does. If someone's a natural mathematician (like Euler or Ramanujan for instance) or physicist or (to a lesser extent) programmer then they are naturally smart. These topics engage the intellect. Being a natural people-person is an innate skill that does not require any proper definition of intelligence, and they don't need to appeal to the intellect much at all to be successful at it.
That isn't to say that being good with people isn't an important skill; it is vitally important. But being good at it does not always require or engage smarts.