When you hang out with friends, you probably don’t spend all your time giving each other advice. Do you know why? Because it’s not really that interesting. Too many online communities base their cause on advice. e.g. A place for photographers/accountants/athletes to share their best tips.
Some advice communities have worked really well. Lucky them. But most don't. You create a social environment where the real affiliation needs aren't being met. A photographer community sharing their best advice benefits everyone. But they want to get to know each other too. They want to talk about their best ever pictures, photographers they admire, upcoming photo shoots and whatever else photographers talk about.
Advice is an additional benefit of bringing together a group of knowledgeable people who want to trust each other. It's not the focus.
Aside, try to base your community around what people do in real life, rather than when you think they want to do on the internet.