Yeah, and we all know why that is, right?  It's because of signature campaigns and bounties, which I assume the other forums OP listed don't have.  Even if bitcoin is going to the moon, there's only so much that can be said about it at any given time--unless you're motivated by money to talk about something.  I joined the Dash forum a while back, and I found it to be pretty dead even though Dash's price was doing just fine.

That would actually be reason #2 in my mind why bitcointalk beats all other crypto forums.  This is kind of where it all began...but I still think it's the bounties and everything else that keeps the traffic coming, not loyalty to Satoshi.