Short answer: because we are protecting you from large amounts of spam. The good news is, moderation is temporary and goes away automatically.
Spam really does get in the way. The flood of spam can drown out real activity.
When a new person creates an account, the odds are that person is a real customer. But a significant fraction are spammers. So we moderate posts for all new users.
What that means for you is this: for a little while your posts will not appear in the forums until reviewed and approved by a real live human being. There can be a delay, occasionally several hours.
If you are active in the forum, post questions or answers, and just do the things you would normally do, in a short while moderation goes away automatically. We have set this up so that before a spammer can reach the point where that happens, we'll spot them. They keep trying, and they keep failing. But being the barrier between them and you is part of what we do.
As a result, you do not see links for real estate projects, solar power schemes, toe fungus cures, and other nonsense ad infinitum. Our apologies if one of them gets by us.
Thanks for your patience.
BTW: Keep in mind, spamming is a zero-tolerance offense. You do it, you're gone. The instant we see it.