For some reason a lot of people are like this. I've explained to people, even people I'm supposedly friends with, that I really hate touching unless I initiate it (and even then I don't like the feeling and I very, very rarely initiate contact anyway), and for the most part that just makes them actively want to touch me. Some do it out of some weird spite, some do it because they think doing so will help me 'get over it'. Apparently nearly no one thinks 'This person dislikes physical contact' then realizes 'I should try not to have physical contact with that person because of that.'.