Nope, steemit is no scam. Due to its open nature bots can try and make money, but that problem is understood and (hopefully) the programmers are working on weeding them out.
Regarding deleting a post. That was done by @steemcleaners. That's no bot, it's a group of people working together to try and keep Steemit clean.
The way they do it needs some finetuning, but a few discussions about this have already started.