The unholy alliance of bloggers pimping credit cards to make money was what really killed the deal. Most of the basic ones were always discussed openly on places like Fatwallet and FT. Some like the small credit union that allowed you to fund unlimited times via credit card were kept secret but there was enough for someone with a bit of free time to figure it out. Now with bloggers pushing cards and showing off all their free travel, rather than be less flamboyant about how much they're milking the system; seminars on this; etc., the gravy train is gone.
Is there still room for someone to earn enough for a decent free roundtrip to anywhere in the world through credit card and bonus churning? Probably, but the days of luxury stays to exotic places are gone, not that they existed much in the first place.