Can't speak for all of them, but I think it's a bandwagon - one says it's fake and doesn't provide evidence, the rest jump on and before you know it everyone says it's fake.
http://www.squidoo.com/neobuxscam (NOT a scam actually, read if you want)
http://www.talkgold.com/forum/r222648-.html another forum that had this discussion
http://neobuxscam.com/ (more people who've actually been paid, I'm sensing a pattern - the sites that have urls like it's a scam are actually fighting -for- neobux).
http://www.squidoo.com/scamneobux (more from the first guy).
PLEASE, DO SOME BLOODY RESEARCH AND PROVIDE YOUR PROOF IF YOU'RE GOING TO SAY ITS A SCAM.
Thank you. Continue, please.