I truly believe fans watch MMA for entertainment. I believe that MMA fans watch the UFC because it is the known for providing entertainment.
What they want you to believe is that having the most talented fighters equates to having the most entertaining fighters and allegedly the result would be the most entertaining fights.
After watching the most recent UFC event, I would say there was an inverse relation between how exciting a fight was compared to how high the fighters were ranked. Jake Shields and Georges St. Pierre had the highest rankings of all the fights and provided the least entertaining fight of the evening. #8 ranked Mark Hominick went against a man touted as the #1 not just in his division but also as a P4P fighter, and provided an amazing display. Rory MacDonald against Nate Diaz also provided fireworks, just a fantastic bout, deserving of Fight of the Night on almost any other card.
I just don't think selling a fight based on how skilled a fighter is will be a great strategy going forward. What brought the UFC to where they are now were the great rivalries to build upto a fight, Ortiz/Shamrock, Ortiz/Liddell, Liddell/Couture, Lesnar/Mir, and many more. Those fights were built off of talented fighters but the entertainment value that they brought was their selling point.
Using TUF to manufacture rivalry seems like their current strategy, but in the future I would love to see more grudge matches. Chael Sonnen vs Michael Bisping, Lesnar vs Mir 3, even give Rampage vs Rashad another shot.
Putting two top contenders in a ring makes sense for the sport, putting two guys who actually hate each other in there makes sense for the fans.