Since when does being private make you look like a weirdo?

[Longwaytogo]

I work as a social media manager so I spend all day on Facebook, twitter and instagram. While I find these sites enjoyable, it's turned me off to what most people do. I'm so tired of the selfies, the showing-off and cry for attention. I used to often post photos of myself all made up and enjoyed the compliments, but I grew tired of it. Now, I rarely post anything unless it's news related. When it comes to my personal life, I have no picture of my fiancé and I. My friends always complain that we shouldn't be so private about our life and we should show off how beautiful of a couple we are. Who cares??? We never even announced our engagement on Facebook - we just called our loved ones to tell them, which I prefer.
When I go on vacation, I don't post personal pics, unless it's one of a beautiful landscape. My friends told me it's strange. That it makes me look like I have something to hide. I just don't feel like putting my life out there. Why am I being branded as a weirdo for being a private person?