Almost From Seven Month i use Bitcointalk Forum. I see that have many Forum same like Bitcointalk. For Example, Cryptotalk, Altcointalk, Bitcoingarden etc Forum. But Why People Always like and Use This Bitcointalk Forum.
Most of the other forums you listed are Bitcointalk copycat; they don't have as many active people as we have in our forum; they also have shitposts and spam on those forums; and, finally, they rarely get forum advertisements from advertising managers.
Bitcointalk is unique, and people enjoy using it because some people, like newbies, like bounties, others want a signature to make a few money, and, as you mentioned, other people ask questions about bitcointalk because it was the original bitcoin forum.