The gulf is so wide that yes it is unjust to give them an autobid over a top 8 team.
Last year, UCF would have received an autobid over Michigan. I think it would have been easy to argue that UCF actually deserved the bid outright at 12-0. But Michigan only lost 2 games and both were to top 6 teams - Notre Dame and Ohio St. Saying that UCF automatically gets in over them is just lazy pandering. UCF had 0 wins over ranked teams. Michigan had 2.
Alabama
Clemson
Oklahoma
Ohio St
Washington
(3) Notre Dame
(5) Georgia
(8) UCF
(7) Michigan