This is a discussion forum, and the only way you can learn is by discussing. Just dropping a topic and not reading to see what people are discussing on the topic doesn't make sense. Make use of the Telegram bot or any other ways to keep track of replies to your topics and posts, interact, and not just drop topics and forget about them.
I can understand this with newbies not getting back to topics they've created because they may not know there's a telegram bot built by a user here to notify users anytime they're mentioned. Again, newbies may not know how to set up notification on this bot or on the thread they've created. Here's the bot link for those who've missed it on the forum @BTTSuperNotifier_bot. For those who don't want to use the bot, they can simply activate "watch" on the thread. It's close to the "reply" tab.
They make new topics to create places for fake discussions and to fish merits and with such people, they will continue as this approach is helpful for getting their signature campaign post quota much more easily and to fish merits from other forum members including merit sources as well as to exchange merits.
You're right about the fishing for merit thing as to why members open threads. It's evident in the way new threads get more merits splashed on them than replies get merited. Until OPs begin to get less attention and merits, I don't see that stopping anytime soon.