The problem with bitcointalk.org right now is it is full of useless threads and posts especially in the altcoin forum. For example if I want to learn more about an altcoin and start a thread or post a question about it, I get a barrage of replies that altcoin "X" is a scam and they suggest to buy altcoin "Y" instead. So it is very hard to get the information that you are looking for. Yes there is google but sometimes it helps to hear first hand experiences from other people and start discussing it.
Well that is what happens when forum is becoming large. You will find that information chaos and you actually need to filter good, interesting and helpful messages out.
If you think Reddit is better in that regard or any other really big forum then let us know. I would really want to know large community where everyone is an expert with amazing knowledge.