It's for solidarity and everything involved in that. I've seen some great tips, I've seen people who feel alone and want to commiserate, I've seen some funny memes, I've seen people with stutters come and emotionally support someone who is struggling. It's a place for a lot of things, but it's not just a place to 'overcome the problem'. Usually a stutter is something you learn to manage, not 'cure'. Having a place where you can talk about it and feel less alone can help immensely.