I personally think it is just another way of engaging with people. I agree your site’s content is the main attraction but social media are more flexible at the same time in terms of discussing different topics with different people.
I don’t like social media icons/links in the header.You place them in the footer if you don’t want distraction. I feel that the sidebar is the middle ground. They are there but not asking for too much attention.
Have you come across some innovative ways of linking to social media?