They may not even know that they are indirectly helping scammers. They mentioned more people for free coins. But they didn't verify that, this was a fake account! In this way Newbies gets trapped, as well as helping others to be trapped. Scammer's easily make fool newbies.
Sometimes replying accounts might also be owned by scammers to create a false picture as thou people are actually participating in the token sale. And the fact that this giveaway scams keep going on and on only shows that the scammers keep gaining out of it. I guess some victims/newbies never learn.