This is going to be a multi-part answer.
1) In the last year or so, I have made peace with being online. I want people to read my books; being online seems to be an aspect of the job of author these days.
2) On the other hand, I think it’s sad that people can’t experience books separate from writers anymore. It’s worth noting that “liking an author” is not at all the same thing as “liking a novel” – and yet I’m not sure many young readers bother to note the difference. And when we make our book-buying decisions based on an author being, say, “funny on twitter,” we are not necessarily buying the best books. Books should not be tribute gifts because authors are amusing. There are several deeply amusing people on Twitter who write boring, pedestrian novels.
3) The flip side again: Just because an author is antisocial doesn’t mean his/her books aren’t beautiful/wonderful/life-changing/amazing. Authors are not always their books. (And books are sometimes more interesting than tweets.)
4) I am still a loner and I still struggle with all of this. I sometimes wish I weren’t online at all. I think, for instance, I am adding nothing to twitter except “sound and fury signifying nothing.” (emphasis on nothing)… I still believe in deliberation and reflection before airing an opinion for the world to see. (The reason I like tumblr, by the way, is because I am impressed by the variety of interests and curatorial* skill you see on it.)
5) On the other hand — that’s my third hand — I like communicating with readers. I like being able to say thank you to those who have enjoyed my books and chosen to tell me so in a thoughtful manner.
6) And so I’m trying to stop fighting everything. I take a deep breath and remind myself of the E.M. Forster quote: “only connect.”
*I know people are sensitive about using the word curatorial outside of a museum context, but I am using it anyway.