In most cases, this is even worse than bots. These are real people, but they are so uninitiated and inactive that you might think they are bots 
Yes this is quite through, it is also hard for the ICO managers to add bots and inactive members inside the telegrams group. Well, basically in order to gain some members, they make their telegram universal just like a tree branch where there is a main branch of group followed by a specific campaign group.