HR is about managing the human capital of a firm, to meet organizational goals. There are some functions which need people interaction, and others that don't. Almost every profession needs people who are good at interacting with others. Can you be a successful football player, if you can't 'interact' with others? A salesperson? An advertising guy? Whatever! The core responsibility of an HR person is to maximize the returns on the money spent in hiring, retaining and developing human resources or human capital – the new age term. Of course, this needs to be done fairly, and within certain legal boundaries. HR has vast scope, and is broadly divided into:
a) Recruitment - includes strategic planning, forecasting, hiring, and selection
b) Learning and Development - training, learning management and administration, career enhancement
c) Performance Management - appraisals and promotions
d) Industrial Relations - mainly for blue-collared jobs, but progressing into white-collared ones as well
e) Compensation - using wages as a strategic tool to gain advantage
f) Consulting – handling traditional HR issues like recruitment, training, performance management, compensation or newer ones like organizational capability, organization design etc.
Now, think about it. Would just being an extrovert, and having a liking for 'talking and interacting with people' qualify you for a job in any of these fields? No, right? You'd have to work just as hard as any other professional, to do well.
And this is not to negate the importance of your communication skills. By all means, being good at written and verbal communication is useful. It’s just that it is a necessary but not sufficient condition to be a good HR manager.