First of all, I believe that a National Champion should be ranked #1 until they prove otherwise by losing a game. Besides that, Clemson has shown that they deserve to be ranked as the #1 team in the nation.

 
Yet Alabama, the team Clemson beat in the National Championship once again reigns atop the rankings by reputation alone. Oh sure they have blown out every team they have faced in true Crimson Tide fashion, but who have they played of significance besides Florida State, the only ranked team they have opposed this season?
 
Per ESPN, Clemson is the first team to ever defeat three top-15 teams in the month of September. The Tigers have beaten Auburn as well as handily beating Louisville with Heisman Trophy winner Lamar Jackson 47-21 and Virginia Tech 31-17 on the road in hostile environments.
 
Clemson has no doubt proved its worthiness to be on top of the mountain.