Poor social skills are a real disadvantage because this is often seen as a moral failure rather than a merely intellectual one. 

Having good social skills is more risk-avoidance than reward-seeking. Having good social skills is about avoiding misfires which cause mutual communication to break down.

It’s possible to be good at speaking but bad at listening or vice versa. A key part of effective speaking is understanding the listerners’ states of mind.

Many good speakers fail to land a joke, for instance, because they don’t understand very well how the person who is listening is actually processing what is being said.

Listening, the effort taken to correctly understand the social context and minds of other people, is probably more like 80% of social skills, with the last 20% being delivery of your message.

The way to improve at anything is to practice.

Feedback is an important mechanism for practice. You try something, you get a response, and you use that response to adjust your output for next time.