When a ranking like this comes out folks dont look at why sucj a ranking may or may not paint an accurate picture. People simply point to the 24/7 talent ranking and say "we're 30th so if our team doesn't finish 30th our coaches have underperformed".
But think about it a little deeper:
40% of our 4-stars that 24/7 based this ranking on were transfers in. We all can agree our 4-star transfers out (for example Gibbs, Ivy, Domineck) have been better than our 4-stars transferring in (for example WR Ezzard, Harris from Bama, DBs Allen from ND & Sims from Michigan). We even had a 5-star transfer in (DE from U of Florida) who had a 2-star effect in 2 years.
Second, the 24/7 rankings do not take into account the AGE of the players, only their rankings. So lets say you have a bunch of 3-star with high composite rankings and 4-star who are very young. That talent has not developed physically in and experientially in your system. They will not perform as well as a team laden with upperclassmen who have developed.
Third, as others have mentioned, games are won and lost in the trenches. Factories stockpile 4-stars at key positions like DT, DE, OL and mature them over years. Best way to make a 4 star QB, RB, or DB bad is to have bad lines.
Strength of schedule matters as well, including how schedule sets up/who you play when/on the road.
Clearly to me we could and should have won a few more games these last 3 years and coaching HAS been a problem. But I am not buying we have the 30th most talented roster.