We all have lives, we don't sit on here all day talking crap about Kimbo. The reason people say he's a stunt to gather more money is because the entire show is based around him. The previews for the show before it started, the commercials, everything, were all based around Kimbo. He is how they are getting so much money off of this season.
The reason why people don't like Kimbo, is mainly because of his fans. Kimbo's career has been mainly retarded fans of his that come from youtube talking about how Kimbo will whoop up on anyone's ass. That has died down now, but that's how it was when he started, as such, "hardcore MMA fans" as you call them, instantly got annoyed and wanted to see him lose all the time. Part of that is still there, which is why so many want to see him lose.
At the end of the day, Kimbo isn't that good of a fighter, he has no ground game, his striking is decent but not nearly enough to make it far in any division, even the HW crap striking division. However, he can gather a lot of money for the UFC as he's very popular, everyone tunes in.