Thanks for the post. Yes just like any social media site there are bots on this site. It's a contentious issue indeed. It could be argued that all users must be people, but it can also be argued that not all bots are malicious/evil and can actually be useful in scraping the internet for useful information. I like to think that Relevant has the tools to encourage useful bots and punish negative ones.
Personally I think if a user has posted a comment, then deletes it then this should be reflected and we should be able to see this. However this may bring additional issues that I have not thought of.
Ultimately there are different sections in the feeds that help negate this ie. Relevant and hot sections which are far harder to game. We also have the spam section so we can see if anyone has been unfairly downvoted and rectify this, so I don't think at this point users are able to "hide" others posts.