It doesn't have to be a 'bot - it can just be one person using multiple logins 'keeping threads alive' to make the site look busier, for commercial reasons. In fact, I think that is what is happening.
Heck, a human can sign up and then turn it over to an auto-posting 'bot.
What would be best is to have an admin simply erase posts that have no useful content. (Posts like "what a pretty color" or "gee, EVs are great!" should just be deleted, preferably within 12 hours.)
I volunteer - give me admin rights, I will keep the site cleaned up.