Considering that multiple sources—including Bob Quinn himself—were able to confirm that the Lions did not receive any firm offers for a trade back, I don’t see how you could possibly knock this pick from a standpoint that you wished the Lions added more picks.
Aside from that, it all comes down to personal preference. If taking a CB and grabbing Okudah was your favorite option, then this has to be a solid A. If Isaiah Simmons or Derrick Brown was your guy, then it might be a softer grade. If Tua Tagovailoa was your guy, seek help.