One thing does not contradict the other

Some salsa dancers are good at dancing with connection. But most are not. I tend to gravitate towards the ones who are better at connection.
So when you see me smiling, it means I am dancing with someone like that (and/or to music I enjoy).
As for kizomba happiness, for me it is often way more intense than salsa, but I am not emoting it like in salsa because I am much more deeply immersed in the experience and connection (and often for a long time with the same partner when the connection is really good). If you see me (and probably it's the same with other people) at my happiest kizzing, I will usually have my eyes closed (unless we are in open position of course) and a slight smile or maybe even no smile, but inside I am feeling a kind of spiritual euphoria, and it is at a much deeper level than salsa happiness, it feels like a euphoric meditation, I forget all about myself and am just deeply in the experience of the dance.
So, just because you don't see a kizomba dancer smiling does not mean there is no happiness, it is just much deeper and more inward than the more emoting kind of salsa happiness.