During the Flashback incident, I was very annoyed at the anti-virus companies that posted very complex command-line procedures for removing a really simple malware program. I've been using UNIX for decades and I don't know what some of those commands do. Obviously their goal was to make the process look much more difficult and scary than it really was.
During that period, I remember making a comment equating MacKeeper to Flashback. R C-R called me on that but I brushed it off because there were so many reports about how bad MacKeeper was. Well, at some point, something clicked. I remembered that one of the most popular anti-MacKeeper links was written by a well-known troll here in Apple Support Communities. I decided to revisit that and discovered it was the same thing the anti-virus companies were doing. So, I tried MacKeeper myself and discovered that the uninstaller worked fine and was even slick enough for me to think "hey, that's cool". MacKeeper is using FSEvents to watch the MacKeeper.app bundle. When the user puts the bundle in the trash, MacKeeper pop-ups and asks the user if they want to delete it. If so, it automatically removes its launch agent.
That is my MacKeeper story. I am never going to recommend it, primarily because of the anti-virus angle. Even without the anti-virus, I don't need the other utilties it provides. I'm not going to recommend anything I don't use. I don't even recommend all the things I do use. MacKeeper's headline of "security, cleaning, and optimization" are things that Mac users just don't need to worry about. But if people want to buy that sort of thing, it is their right.
I cannot verify any of these reports of shady businesses practices from Zeobit. As I have disproved some of them, I am disinclined to believe any of them. I have low opinions of a number of other, much larger, companies but I am not going to directly air my suspicions in public. I will do my best to say good things and refute misinformation about their competitors, such as Apple, instead.