If Cam Calhoun had signed with BYU, he would still be a 90. If Tanuvasa had signed with Michigan, he still would have been rated an 86.

That's not 247 having some conspiracy against BYU. It's downgrading players who haven't played much and then (imo) making an honest mistake on Tanuvasa.

They're trying to decide in a hurry and so they look at his stats

Freshman: 6 tackles, 1 sack (in 4 games)
RS Freshman: 27 tackles, 2 sacks (in 13 games)
RS Sophomore: 17 tackles, 1 sack (in 7 games)

Those don't tell the story of how good he is, especially in a Utah scheme that asks him to take blockers and free up opportunity for others, but if someone is looking on the surface, they're going to not be as impressed as they should be, especially given his recent injury history.

That's not to dismiss how good he is...but I get why a quick rating may not reflect it