I must admit it did sting a little when I got my first unfollow but I soon realised that that is part of the game and something you really need to get used to on any social media. I like to see development in those that I follow as it keeps me interested in what they are at and sometimes people can clog your feed with too much samey content, especially if they post too often. People should not take it personally if you have to cull them. We live in an attention economy and sometimes you just don't have enough attention to spread out.